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 A377828 #11 Feb 16 2025 08:34:07
%S A377828 1,4,21,193,2669,48711,1113325,30615019,984983193,36319515355,
%T A377828 1510538562641,69968975169567,3572684914283941,199389519518767111,
%U A377828 12075888110164192917,788850329621989132771,55289606764547108653361,4138807268239824817387443,329564746571982961088975257
%N A377828 E.g.f. satisfies A(x) = (1 + x)^3 * exp(x * A(x)).
%H A377828 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/LambertW-Function.html">Lambert W-Function</a>.
%F A377828 E.g.f.: (1+x)^3 * exp( -LambertW(-x*(1+x)^3) ).
%F A377828 E.g.f.: -LambertW(-x*(1+x)^3)/x.
%F A377828 a(n) = n! * Sum_{k=0..n} (k+1)^(k-1) * binomial(3*k+3,n-k)/k!.
%o A377828 (PARI) a(n) = n!*sum(k=0, n, (k+1)^(k-1)*binomial(3*k+3, n-k)/k!);
%Y A377828 Cf. A377826, A377827.
%Y A377828 Cf. A377741, A377811.
%K A377828 nonn
%O A377828 0,2
%A A377828 _Seiichi Manyama_, Nov 09 2024