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 A384136 #9 May 20 2025 08:53:42
%S A384136 1,11,191,4578,140274,5238132,230784840,11720201616,674092013040,
%T A384136 43310839531680,3074579815271040,238983481496188800,
%U A384136 20187063842072319360,1841332369689189619200,180372122189263722009600,18885338733119777188300800,2104722524872544008142592000
%N A384136 a(n) = (3*n)!/(2*n)! * Sum_{k=1..n} 1/(2*n+k).
%F A384136 a(n) = Sum_{k=0..n} k * (2*n+1)^(k-1) * |Stirling1(n,k)|.
%F A384136 a(n) = n! * [x^n] (-log(1 - x)/(1 - x)^(2*n+1)).
%o A384136 (PARI) a(n) = sum(k=0, n, k*(2*n+1)^(k-1)*abs(stirling(n, k, 1)));
%Y A384136 Cf. A098118, A384137.
%Y A384136 Cf. A383678.
%K A384136 nonn
%O A384136 1,2
%A A384136 _Seiichi Manyama_, May 20 2025