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 A245570 #9 Aug 01 2019 03:49:24
%S A245570 1,1,1,3,1,1,2,3,1,1,1,1,3,1,1,3,1,1,3,1,1,7,3,1,1,3,1,1,4,7,3,1,1,3,
%T A245570 1,1,9,2,7,3,1,1,3,1,1,1,9,1,7,3,1,1,3,1,1,11,1,9,1,7,3,1,1,3,1,1,6,
%U A245570 11,1,9,1,7,3,1,1,3,1,1,13,3,11,1,9,1,7,3,1,1,3,1,1
%N A245570 Rectangular array A read by (upward) antidiagonals: A(n,k) = n/gcd(n,10^k), n,k >= 1.
%C A245570 Columns of A converge to A132740.
%e A245570 Array A begins:
%e A245570 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ...
%e A245570 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ...
%e A245570 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, ...
%e A245570 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, ...
%e A245570 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ...
%e A245570 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, ...
%e A245570 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, ...
%e A245570 4, 2, 1, 1, 1, 1, 1, 1, 1, 1, ...
%e A245570 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, ...
%e A245570 ...
%t A245570 Grid[Table[n/GCD[n, 10^k], {n, 12}, {k, 12}]] (* Array *)
%t A245570 Flatten[Table[(n - k + 1)/GCD[n - k + 1, 10^k], {n, 13}, {k, n}]] (* Array antidiagonals flattened *)
%Y A245570 Cf. A132740.
%K A245570 nonn,tabl
%O A245570 1,4
%A A245570 _L. Edson Jeffery_, Jul 25 2014