TECO, 45 bytes
1un@i/
/10<@i/01234567890/jl10<qnc0a^t>jtl%n>
A (fairly) straightforward implementation of Rod's Python answer.
1un !initialize register n to 1!
@i/<nl>/ !insert a newline!
10< !loop for 10 rows!
@i/01234567890/ !insert the mysterious string of digits!
j !move point to start of buffer!
l !move forward past the newline!
10< !loop for 10 digits on a line!
qnc !move point forward by n characters!
0a^t !print the character at point!
> !end inner loop!
j !move point to start of buffer!
t !print (empty) line!
l !move to start of digit string!
%n !increment register n (for next line)!
> !end outer loop!
Using <ESC>-terminated inserts and a control character for the ^T command would save another three five bytes, at the expense of readability.
Using Martin's mod-11/mod-10 formula actually makes it longer at 43 bytes using controls for ^A and ^T, mostly because TECO doesn't have a mod operator.
0ur10<%run10<qn-10"g-11%n'qn\r0a^Tqr%n>^a
^A>
Mod 11 is done in an ongoing fashion by incrementing the number in qn by -11 whenever it exceeds 10. The qn\r0a^T
sequence inserts the number in the editing buffer as decimal digits, reverses past the last digit, retrieves it from the buffer and types it, essentially doing mod-10.
I expected it to be shorter. Oh, well.
6Welcome to PPCG, and amazing first answer! We hope you'll stick around and contribute more :-) – ETHproductions – 2017-06-26T21:50:47.033
@ETHproductions thanx :))) – mdahmoune – 2017-07-06T12:03:05.247