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 A265945 #34 Mar 05 2025 06:35:07
%S A265945 1,2,6,18,64,220,888,3192,15104,48096,338400,285120,13728768,
%T A265945 -75484032,1327431168,-15621137280,232048220160,-3468200017920,
%U A265945 56208508250112,-959557688285184,17344153658234880,-330228975428997120,6611419866845122560,-138844103855232061440
%N A265945 n-th derivative of x^(2*x) at x=1.
%H A265945 Robert Israel, <a href="/A265945/b265945.txt">Table of n, a(n) for n = 0..450</a>
%F A265945 E.g.f.: (x+1)^(2*x+2).
%F A265945 From _Robert Israel_, Dec 23 2015: (Start)
%F A265945 a(n) = Sum_{k=0..n} binomial(n,j)*A005727(j)*A005727(n-j).
%F A265945 a(n+1) = 2*(a(n) + Sum_{k=0..n-1} (-1)^(n-1-k)*n!*a(k)/((n-k)*k!)). (End)
%p A265945 S:= series((x+1)^(2*x+2), x, 51):
%p A265945 seq(coeff(S,x,j)*j!, j=0..50); # _Robert Israel_, Dec 23 2015
%t A265945 With[{nn=30},CoefficientList[Series[(x+1)^(2x+2),{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, May 20 2018 *)
%Y A265945 Cf. A005727.
%K A265945 sign
%O A265945 0,2
%A A265945 _Ben Paul Thurston_, Dec 23 2015
%E A265945 More terms from _Alois P. Heinz_, Dec 23 2015