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 A383172 #10 Apr 18 2025 08:44:28
%S A383172 0,0,0,1,18,295,5115,96838,2012724,45825148,1137703140,30643915984,
%T A383172 891001127016,27835772321344,930387252759328,33141746095999552,
%U A383172 1253756533365348992,50210676392866266880,2122613151692627299584,94470824166941637093376
%N A383172 Expansion of e.g.f. -log(1 + log(1 - 2*x)/2)^3 / 6.
%F A383172 a(n) = Sum_{k=3..n} 2^(n-k) * |Stirling1(n,k) * Stirling1(k,3)|.
%o A383172 (PARI) a(n) = sum(k=3, n, 2^(n-k)*abs(stirling(n, k, 1)*stirling(k, 3, 1)));
%Y A383172 Cf. A383170, A383171.
%Y A383172 Cf. A341588, A383164.
%K A383172 nonn
%O A383172 0,5
%A A383172 _Seiichi Manyama_, Apr 18 2025