This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A346393 #38 Mar 05 2022 11:07:24 %S A346393 1,2,3,4,5,6,7,8,9,10,1,11,2,12,13,14,5,15,16,17,18,19,10,20,1,21,2, %T A346393 22,23,4,24,5,25,26,27,28,29,10,30,1,31,2,32,3,33,34,5,35,6,36,37,38, %U A346393 39,10,20,40,1,41,2,42,43,4,44,5,15,45,46,47,8,48,49,10,50 %N A346393 Irregular triangle read by rows: the n-th row gives the divisors of n ending with the final digit of n. %H A346393 Stefano Spezia, <a href="/A346393/b346393.txt">First 5000 rows of the triangle, flattened</a> %e A346393 The triangle begins: %e A346393 1 %e A346393 2 %e A346393 3 %e A346393 4 %e A346393 5 %e A346393 6 %e A346393 7 %e A346393 8 %e A346393 9 %e A346393 10 %e A346393 1 11 %e A346393 2 12 %e A346393 13 %e A346393 14 %e A346393 5 15 %e A346393 16 %e A346393 17 %e A346393 18 %e A346393 19 %e A346393 10 20 %e A346393 1 21 %e A346393 2 22 %e A346393 23 %e A346393 4 24 %e A346393 5 25 %e A346393 26 %e A346393 27 %e A346393 28 %e A346393 29 %e A346393 10 30 %e A346393 1 31 %e A346393 2 32 %e A346393 3 33 %e A346393 34 %e A346393 5 35 %e A346393 6 36 %e A346393 37 %e A346393 38 %e A346393 39 %e A346393 10 20 40 %e A346393 ... %t A346393 r[n_]:=Drop[Select[Divisors[n],(Mod[#,10]==Mod[n,10]&)]]; Flatten[Array[r, 50]] %o A346393 (Python) %o A346393 from sympy import divisors %o A346393 def auptorow(nn): %o A346393 for n in range(1, nn+1): %o A346393 yield from [d for d in divisors(n) if d%10 == n%10] %o A346393 print([an for an in auptorow(50)]) # _Michael S. Branicky_, Jul 21 2021 %o A346393 (PARI) row(n) = select(x->(x%10) == (n%10), divisors(n)); \\ _Michel Marcus_, Jul 25 2021 %Y A346393 Cf. A010879, A027750, A330348 (row length). %K A346393 nonn,tabf,base %O A346393 1,2 %A A346393 _Stefano Spezia_, Jul 21 2021