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 A059440 #8 Jun 25 2019 09:12:46 %S A059440 1,3,12,58,327,2109,15366,125316,1135329,11348623,124359336, %T A059440 1484796894,19204214363,267627706257,3998828758938,63777662250440, %U A059440 1081442839245381,19426122224995107,368492543629967292 %N A059440 A diagonal of A059438. %D A059440 L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 262 (#14). %H A059440 Vaclav Kotesovec, <a href="/A059440/b059440.txt">Table of n, a(n) for n = 3..400</a> %F A059440 G.f.: (1-1/Sum (k! x^k ))^3. %F A059440 a(n) ~ 3*sqrt(2*Pi) * n^(n - 3/2) / exp(n). - _Vaclav Kotesovec_, Jun 25 2019 %K A059440 nonn,easy %O A059440 3,2 %A A059440 _N. J. A. Sloane_, Feb 01 2001 %E A059440 More terms from _Vladeta Jovovic_, Mar 04 2001