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 A385441 #11 Jul 04 2025 04:57:29
%S A385441 1,1,7,99,2145,62985,2340135,105306075,5568833025,338526428625,
%T A385441 23261601738375,1783052341945875,150846228128621025,
%U A385441 13961656447904590425,1403387191229030382375,152244874971071908900875,17729607712540283209274625,2206069759660369525039742625,292095560880436494680262138375
%N A385441 E.g.f. A(x) satisfies A(x) = exp( arcsinh(x * A(x)^3) ).
%F A385441 E.g.f. A(x) satisfies A(x) = (1 + 2*x*A(x)^4)^(1/2).
%F A385441 a(n) = 2^n * n! * binomial((4*n+1)/2,n)/(4*n+1).
%F A385441 a(n) = Sum_{k=0..n} (3*n+1)^(k-1) * i^(n-k) * A385343(n,k), where i is the imaginary unit.
%F A385441 a(n) ~ 2^(3*n-1) * n^(n-1) / exp(n). - _Vaclav Kotesovec_, Jul 04 2025
%o A385441 (PARI) a(n) = 2^n*n!*binomial((4*n+1)/2, n)/(4*n+1);
%Y A385441 Cf. A001147, A385369, A385440, A385442.
%Y A385441 Cf. A385343.
%K A385441 nonn
%O A385441 0,3
%A A385441 _Seiichi Manyama_, Jun 29 2025