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 A292894 #32 Jul 10 2022 08:09:13 %S A292894 1,1,-1,1,0,0,1,0,-2,1,1,0,0,-3,1,1,0,0,-6,8,-2,1,0,0,0,-12,55,-9,1,0, %T A292894 0,0,-24,-20,84,-9,1,0,0,0,0,-60,330,-637,50,1,0,0,0,0,-120,-120,2478, %U A292894 -4992,267,1,0,0,0,0,0,-360,-210,11704,-10593,413,1,0,0,0,0,0,-720,-840,19824,-15192,92060,-2180 %N A292894 Square array T(n,k), n>=0, k>=0, read by antidiagonals, where column k is the expansion of e.g.f. exp(x^k * (1 - exp(x))). %H A292894 Seiichi Manyama, <a href="/A292894/b292894.txt">Antidiagonals n = 0..139, flattened</a> %F A292894 From _Seiichi Manyama_, Jul 09 2022: (Start) %F A292894 T(n,k) = n! * Sum_{j=0..floor(n/(k+1))} (-1)^j * Stirling2(n-k*j,j)/(n-k*j)!. %F A292894 T(0,k) = 1 and T(n,k) = -(n-1)! * Sum_{j=k+1..n} j/(j-k)! * T(n-j,k)/(n-j)! for n > 0. (End) %e A292894 Square array begins: %e A292894 1, 1, 1, 1, 1, ... %e A292894 -1, 0, 0, 0, 0, ... %e A292894 0, -2, 0, 0, 0, ... %e A292894 1, -3, -6, 0, 0, ... %e A292894 1, 8, -12, -24, 0, ... %e A292894 -2, 55, -20, -60, -120, ... %o A292894 (PARI) T(n, k) = n!*sum(j=0, n\(k+1), (-1)^j*stirling(n-k*j, j, 2)/(n-k*j)!); \\ _Seiichi Manyama_, Jul 09 2022 %Y A292894 Columns k=0..2 give A000587, A292893, A292951. %Y A292894 Rows n=0..1 give A000012, (-1)*A000007. %Y A292894 Main diagonal gives A000007. %Y A292894 Cf. A292892, A355607. %K A292894 sign,tabl %O A292894 0,9 %A A292894 _Seiichi Manyama_, Sep 26 2017