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 A380030 #9 Jan 10 2025 10:09:55
%S A380030 1,-2,-6,-26,-208,-2570,-42332,-865718,-21110224,-597416786,
%T A380030 -19239912340,-694646155742,-27785653906232,-1219574936748506,
%U A380030 -58274685177526300,-3011159013528002150,-167299112903683007392,-9945379044947061586850,-629870278061691615041828
%N A380030 Expansion of e.g.f. (1 - 3*x*exp(x))^(2/3).
%F A380030 a(n) = n! * Sum_{k=0..n} (-3)^k * k^(n-k) * binomial(2/3,k)/(n-k)!.
%o A380030 (PARI) a(n) = n!*sum(k=0, n, (-3)^k*k^(n-k)*binomial(2/3, k)/(n-k)!);
%Y A380030 Cf. A004989, A380029.
%K A380030 sign,easy
%O A380030 0,2
%A A380030 _Seiichi Manyama_, Jan 09 2025