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 A264437 #23 Nov 13 2023 06:50:09
%S A264437 1,1,2,0,-56,0,15840,0,-17297280,0,50791104000,0,-327856732600320,0,
%T A264437 4080179409546240000,0,-89192941330901151744000,0,
%U A264437 3193957788339335451033600000,0,-177450861021098776794591068160000,0,14644425624059165645548485417369600000,0
%N A264437 a(n) = Bernoulli(n, 1)*Pochhammer(n+1, n).
%F A264437 a(n) = CatalanNumber(n)*Sum_{k=0..n} Eulerian1(n, k)*k!*(n - k)!*(-1)^k. # _Peter Luschny_, Aug 13 2022
%p A264437 seq(pochhammer(n+1,n)*bernoulli(n,1),n=0..23);
%p A264437 # For illustration:
%p A264437 e1 := proc(n, k) combinat:-eulerian1(n, k) end:
%p A264437 catalan := n -> binomial(2*n, n)/(n + 1):
%p A264437 a := n -> catalan(n)*add(e1(n, k)*k!*(n - k)!*(-1)^k, k = 0..n): # _Peter Luschny_, Aug 13 2022
%t A264437 a[n_] := BernoulliB[n, 1]*Pochhammer[n+1, n];
%t A264437 Table[a[n], {n, 0, 23}] (* _Jean-François Alcover_, Nov 13 2023 *)
%o A264437 (Sage)
%o A264437 def A264437(n):
%o A264437 return bernoulli_polynomial(1,n)*factorial(2*n)//factorial(n)
%o A264437 [A264437(n) for n in range(24)]
%o A264437 (PARI) a(n) = subst(bernpol(n), 'x, 1) *(2*n)!/n!; \\ _Michel Marcus_, Nov 13 2023
%Y A264437 Cf. A001813, A027641, A268432, A000108 (Catalan), A173018 (Eulerian first order).
%K A264437 sign
%O A264437 0,3
%A A264437 _Peter Luschny_, Feb 14 2016
%E A264437 Name and data changed to comply with Bernoulli(n,1) by _Peter Luschny_, Aug 13 2022