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 A168136 #14 Sep 08 2022 08:45:48
%S A168136 1,1,-2,20,-504,25200,-2189088,302702400,-62564261760,18427508985600,
%T A168136 -7449695786856960,4010313259477324800,-2803674333549374208000,
%U A168136 2492728196309155284480000,-2768630339381333070099456000
%N A168136 a(n) = Bernoulli(2n)*(2n+1)!/n!.
%C A168136 Given by alternating sums of coefficients of polynomials spawned by sums of binomial(n,k)^2*k^(2m). - _John M. Campbell_, Nov 30 2011
%H A168136 Vincenzo Librandi, <a href="/A168136/b168136.txt">Table of n, a(n) for n = 0..100</a>
%t A168136 Table[BernoulliB[2*n]*(2*n+1)!/n!, {n, 0, 20}]
%o A168136 (PARI) a(n)=bernfrac(2*n)*(2*n+1)!/n!
%o A168136 (Magma) [Bernoulli(2*n)*Factorial(2*n+1)/Factorial(n): n in [0..20]]; // _Vincenzo Librandi_, Jul 14 2016
%Y A168136 Cf. A001332, A004193.
%K A168136 sign
%O A168136 0,3
%A A168136 _Franklin T. Adams-Watters_, Nov 19 2009