PHP, 323 Bytes
Same way as other count the coins until the sum of the two last elements in the array
<?function t($g){rsort($g);$m=array_slice($g,1);for($y=1,$i=$g[0];$i<$g[0]+$m[0];$i++){$a=$b=$i;$p=0;$r=$s=[];while($a||$b){$o=$n=0;$g[$p]<=$a?$a-=$r[]=$g[$p]:$o=1;($m[$p]??1)<=$b?$b-=$s[]=$m[$p]:$n=1;$p+=$o*$n;}$y*=count($r)<=count($s);}return$y;}for($i=0,$t=1;++$i<count($a=$_GET[a]);)$t*=t(array_slice($a,0,$i+1));echo$t;
My best and longest answer I believe >370 Bytes
I give only an expanded version cause it is longer then my answer before
for($x=1,$n=0,$f=[];++$n<count($a)-1;){
$z=array_slice($a,0,$n+1);
$q=$a[$n]-$a[$n-1];
$i=array_fill(1,$c=max($a[$n+1]??1,11),"X");#$q*$a[$n]
$f=range($a[$n],$c,$q);
$f[]=2*$a[$n];
for($d=[$z[$n]],$j=0;$j<$n;){
$f[]=$a[$n]+$d[]=$z[$n]-$z[$j++];
}
while($f){
$i[$t=array_pop($f)]="T";
foreach($d as $g)
if(($l=$t+$g)<=$c)$f[]=$l;
}
foreach($i as$k=>$v){
if(in_array($k,$z))$i[$k]="S";
}
#var_dump($i);
if($i[$a[$n+1]]=="X")$x*=0;
}
echo$x;
Explanation for this answer
Online Version
Set all in the array to false == X
Set all numbers in the array you control to S
Found differences between the last S and the other S or 0
Start at last S in the array
Set all number to D Where Last S+ one of all differences
Begin at all D
SET "T" to D values in the array
GOTO 5 Repeat it with all found D I did it not really in the code
If next item in the Array has X it is a false case else True
Additional Steps
Difference is in the case in the snippet 3
Between 1 and 4 are 2 X
This means you need the second D by Step 5. After this value in this case 10 are all cases true
I could see so far that there is a relationship between difference and the count in the array you control to calculate how much D (Step 5) you need to get the point before you find the last false case.
You set multiple values from the last item directly to true.
These Points can make a difference to decide if it could been that the greedy count of coins with the next value is same then the multiple of the last in the array.
On the other way you can set enemy
Set first enemy at 1+Last S
From this Point add each value in the array to set the next enemies
Start with last enemy Goto 2
If you now have enemies and true cases in it the
probability grows that the counts can be the same
With more D the probability sinks.
table{width:80%}
td,th{width:45%;border:1px solid blue;}
<table>
<caption>Working [1,4]</caption>
<tr><th>Number</th><th>Status</th></tr>
<tr><td>1</td><td>S</td></tr>
<tr><td>2</td><td>X</td></tr>
<tr><td>3</td><td>X</td></tr>
<tr><td>4</td><td>S</td></tr>
<tr><td>5</td><td>X</td></tr>
<tr><td>6</td><td>X</td></tr>
<tr><td>7</td><td>D3</td></tr>
<tr><td>8</td><td>D4</td></tr>
<tr><td>9</td><td>X</td></tr>
<tr><td>10</td><td>D3D3</td></tr>
<tr><td>11</td><td>D4D3</td></tr>
<tr><td>12</td><td>D4D4</td></tr>
<tr><td>13</td><td>D3D3D3</td></tr>
<tr><td>14</td><td>D4D3D3</td></tr>
<tr><td>15</td><td>D4D4D4</td></tr>
<tr><td>16</td><td>D4D4D3</td></tr>
</table>
<ul>
<li>S Number in Array</li>
<li>D Start|End point TRUE sum Differences from last S</li>
<li>X False</li>
</ul>
plus ? Bytes Thank You @JonathanAllan to give me wrong test cases
262 Bytes
Nearly but not good enough 4 wrong testcase in the moment
test cases [1,16,256] before should true after false
<?for($q=[1],$i=0,$t=1,$w=[0,1];++$i<count($a=$_GET[v]);$w[]=$a[$i],$q[]=$m)($x=$a[$i]-$a[$i-1])>=($y=$a[$i-1]-$a[$i-2])&&((($x)%2)==(($m=(($a[$i]+$x)*$a[$i-1])%$a[$i])%2)&&$m>array_sum($q)||(($x)%2)==0&&(($a[$i]-$a[$i-2])*2%$y)==0||in_array($m,$w))?:$t=0;echo$t;
Ascending Order of the Array
Explanation
for($q=[1],$i=0,$t=1,$w=[0,1] # $t true case $q array for modulos $w checke values in the array
;++$i<count($a=$_GET[v]) #before loop
;$w[]=$a[$i],$q[]=$m) # after loop $q get the modulo from the result and fill $w with the checked value
($x=$a[$i]-$a[$i-1])>=($y=$a[$i-1]-$a[$i-2])
# First condition difference between $a[i] and $a[$i-1] is greater or equal $a[$i-1] and $a[$i-2]
# if $a[$-1] == 1 $a[$i-2] will be interpreted as 0
&& ## AND Operator with the second condition
(
(($x)%2)== # See if the difference is even or odd
(($m=(($a[$i]+$x)*$a[$i-1])%$a[$i])%2)&&$m>array_sum($q)
# After that we multiply the result with the lower value *$a[$i-1]
# for this result we calculate the modulo of the result with the greater value %$a[$i]
# if the difference and the modulo are both even or odd this belongs to true
# and the modulo of the result must be greater as the sum of these before
# Ask me not why I have make try and error in an excel sheet till I see this relation
||
(($x)%2)==0&&(($a[$i]-$a[$i-2])*2%$y)==0 # or differce modulator is even and difference $a[$i],$a[$i-1] is a multiple of half difference $a[$i-1],$a[$i-2]
||
in_array($m,$w) # if the modulo result is equal to the values that we have check till this moment in the array we can also neglect the comparison
)
?:$t=0; # other cases belongs to false
echo$t; #Output
It looks like that what I have seen
the table contains values from [1,2,3,4,5,6] and I change only the last item until 9. for 2to3 and 4to5 we create the value of the lower value in the modulo calculation
table{width:95%;}th,td{border:1px solid}
<table><tr><th>difference</th><td></td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td></tr>
<tr><th>difference modulo 2</th><td></td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td></tr>
<tr><th>value</th><td>1</td><td>2</td><td>3</td><td>4</td><td>5</td><td>6</td></tr>
<tr><th>result</th><td></td><td>3</td><td>8</td><td>15</td><td>24</td><td>35</td></tr>
<tr><th>modulo value great</th><td></td><td>1</td><td>2</td><td>3</td><td>4</td><td>5</td></tr>
<tr><th>modulo 2</th><td></td><td>1</td><td>0</td><td>1</td><td>0</td><td>1</td></tr>
<tr><th></th><td></td><td></td><td></td><td></td><td></td><td></td></tr>
<tr><th>difference</th><td></td><td>1</td><td>1</td><td>1</td><td>1</td><td>2</td></tr>
<tr><th>difference modulo 2</th><td></td><td>1</td><td>1</td><td>1</td><td>1</td><td>0</td></tr>
<tr><th>value</th><td>1</td><td>2</td><td>3</td><td>4</td><td>5</td><td>7</td></tr>
<tr><th>result</th><td></td><td>3</td><td>8</td><td>15</td><td>24</td><td>45</td></tr>
<tr><th>modulo value great</th><td></td><td>1</td><td>2</td><td>3</td><td>4</td><td>3</td></tr>
<tr><th>modulo 2</th><td></td><td>1</td><td>0</td><td>1</td><td>0</td><td>1</td></tr>
<tr><th></th><td></td><td></td><td></td><td></td><td></td><td></td></tr>
<tr><th>difference</th><td></td><td>1</td><td>1</td><td>1</td><td>1</td><td>3</td></tr>
<tr><th>difference modulo 2</th><td></td><td>1</td><td>1</td><td>1</td><td>1</td><td>1</td></tr>
<tr><th>value</th><td>1</td><td>2</td><td>3</td><td>4</td><td>5</td><td>8</td></tr>
<tr><th>result</th><td></td><td>3</td><td>8</td><td>15</td><td>24</td><td>55</td></tr>
<tr><th>modulo value great</th><td></td><td>1</td><td>2</td><td>3</td><td>4</td><td>7</td></tr>
<tr><th>modulo 2</th><td></td><td>1</td><td>0</td><td>1</td><td>0</td><td>1</td></tr>
<tr><th></th><td></td><td></td><td></td><td></td><td></td><td></td></tr>
<tr><th>difference</th><td></td><td>1</td><td>1</td><td>1</td><td>1</td><td>4</td></tr>
<tr><th>difference modulo 2</th><td></td><td>1</td><td>1</td><td>1</td><td>1</td><td>0</td></tr>
<tr><th>value</th><td>1</td><td>2</td><td>3</td><td>4</td><td>5</td><td>9</td></tr>
<tr><th>result</th><td></td><td>3</td><td>8</td><td>15</td><td>24</td><td>65</td></tr>
<tr><th>modulo value great</th><td></td><td>1</td><td>2</td><td>3</td><td>4</td><td>2</td></tr>
<tr><th>modulo 2</th><td></td><td>1</td><td>0</td><td>1</td><td>0</td><td>0</td></tr></table>
@Geobits not in every case it means more that the difference growing or equal from the smallest coin to the largest – Jörg Hülsermann – 2016-10-13T20:51:55.677
@JörgHülsermann That's not really good enough either. [1, 6, 13] has a growing difference, but it still fails on something like 18 (13+15 instead of 63). – Geobits – 2016-10-13T20:55:56.487
16
These are called Canonical Coin Systems. This short paper gives a polynomial-time algorithm for checking whether a coin system is canonical (though a less efficient method might be golfier). An interesting test case is making 37 cents from
– xnor – 2016-10-13T23:15:43.19725, 9, 4, 1(from this math.SE post) -- even though each coin is bigger than the sum of the smaller ones, the non-greedy25, 4, 4, 4beats the greedy25, 9, 1, 1, 1.1@xnor Note that
9, 4, 1->4, 4, 4being better than9, 1, 1, 1is a tighter example. – isaacg – 2016-10-14T01:01:12.073