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 A385528 #10 Jul 02 2025 14:42:34
%S A385528 1,1,-3,-47,1385,119601,-22345691,-10181013695,10346973518097,
%T A385528 23934447308323873,-122307331801326167539,-1379021793666951568998159,
%U A385528 33874331587448813081748999673,1804181313330860398948564389193681,-206892703326367302570264123699846971211
%N A385528 E.g.f. A(x) satisfies A(x) = exp(x*A(-2*x)).
%F A385528 a(0) = 1; a(n) = Sum_{k=0..n-1} (k+1) * (-2)^k * binomial(n-1,k) * a(k) * a(n-1-k).
%o A385528 (Ruby)
%o A385528 def ncr(n, r)
%o A385528 return 1 if r == 0
%o A385528 (n - r + 1..n).inject(:*) / (1..r).inject(:*)
%o A385528 end
%o A385528 def A(q, n)
%o A385528 ary = [1]
%o A385528 (1..n).each{|i| ary << (0..i - 1).inject(0){|s, j| s + (j + 1) * q ** j * ncr(i - 1, j) * ary[j] * ary[i - 1 - j]}}
%o A385528 ary
%o A385528 end
%o A385528 def A385528(n)
%o A385528 A(-2, n)
%o A385528 end
%Y A385528 Cf. A000272, A096538, A141369, A385526, A385527, A385529, A385530.
%Y A385528 Cf. A015097.
%K A385528 sign
%O A385528 0,3
%A A385528 _Seiichi Manyama_, Jul 02 2025