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 A375722 #12 Aug 25 2024 09:56:09 %S A375722 1,9,117,1962,40122,966276,26755812,836862192,29167596504, %T A375722 1120629465432,47044646845848,2142210019297680,105154320625284240, %U A375722 5534780654854980000,310945503593770489440,18570787974013838515200,1174884522886771261079040 %N A375722 Expansion of e.g.f. 1 / (1 + 3 * log(1 - x))^3. %F A375722 a(n) = (1/2) * Sum_{k=0..n} 3^k * (k+2)! * |Stirling1(n,k)|. %F A375722 a(0) = 1; a(n) = 3 * Sum_{k=1..n} (2*k/n + 1) * (k-1)! * binomial(n,k) * a(n-k). %o A375722 (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(1/(1+3*log(1-x))^3)) %o A375722 (PARI) a(n) = sum(k=0, n, 3^k*(k+2)!*abs(stirling(n, k, 1)))/2; %Y A375722 Cf. A354263, A375721. %Y A375722 Cf. A354122, A367475. %Y A375722 Cf. A367473. %K A375722 nonn %O A375722 0,2 %A A375722 _Seiichi Manyama_, Aug 25 2024