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 A293908 #12 Oct 21 2017 09:43:48 %S A293908 1,1,1,1,1,2,1,1,3,8,1,1,5,19,38,1,1,9,49,121,238,1,1,17,133,409,1041, %T A293908 1828,1,1,33,373,1441,4841,10651,16096,1,1,65,1069,5233,23601,66541, %U A293908 121843,160604,1,1,129,3109,19441,119441,442681,1006825,1575729,1826684,1,1 %N A293908 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f.: exp(Sum_{j>=1} j^(k-1)*A000009(j)*x^j). %H A293908 Seiichi Manyama, <a href="/A293908/b293908.txt">Antidiagonals n = 0..139, flattened</a> %F A293908 A(0,k) = 1 and A(n,k) = (n-1)! * Sum_{j=1..n} j^k*A000009(j)*A(n-j,k)/(n-j)! for n > 0. %e A293908 Square array begins: %e A293908 1, 1, 1, 1, 1, ... %e A293908 1, 1, 1, 1, 1, ... %e A293908 2, 3, 5, 9, 17, ... %e A293908 8, 19, 49, 133, 373, ... %e A293908 38, 121, 409, 1411, 5233, ... %e A293908 238, 1041, 4841, 23601, 119441, ... %Y A293908 Columns k=0..2 give A293839, A293840, A293841. %Y A293908 Rows n=0-1 give A000012. %Y A293908 Cf. A293796. %K A293908 nonn,tabl %O A293908 0,6 %A A293908 _Seiichi Manyama_, Oct 19 2017