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 A305466 #22 Jun 02 2018 13:06:17 %S A305466 1,1,0,1,1,-1,1,2,1,0,1,3,7,2,1,1,4,17,40,7,0,1,5,31,150,313,33,-1,1, %T A305466 6,49,368,1783,3090,191,0,1,7,71,730,5857,26595,36767,1304,1,1,8,97, %U A305466 1272,14551,116772,476927,511648,10241,0,1,9,127,2030,30457,363045,2796671,9988872,8149601,90865,-1 %N A305466 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where A(n,k) is Sum_{j=0..floor(n/2)} ((n-j)!/j!)*binomial(n-j,j)*k^(n-2*j)*(-1)^j. %H A305466 Seiichi Manyama, <a href="/A305466/b305466.txt">Antidiagonals n = 0..139, flattened</a> %F A305466 A(n,k) = k*n*A(n-1,k) - A(n-2,k) for n>1. %e A305466 Square array begins: %e A305466 1, 1, 1, 1, 1, 1, ... %e A305466 0, 1, 2, 3, 4, 5, ... %e A305466 -1, 1, 7, 17, 31, 49, ... %e A305466 0, 2, 40, 150, 368, 730, ... %e A305466 1, 7, 313, 1783, 5857, 14551, ... %Y A305466 Columns k=0-3 give A056594, A058797, A093985(n-1), A305471. %Y A305466 Rows n=0-2 give A000012, A001477, A056220. %Y A305466 Main diagonal gives A305467. %Y A305466 Cf. A305401. %K A305466 sign,tabl %O A305466 0,8 %A A305466 _Seiichi Manyama_, Jun 02 2018