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 A385140 #14 Jun 19 2025 10:24:21
%S A385140 1,2,0,-22,-16,1042,1792,-116758,-330496,24101090,96518144,
%T A385140 -7976308118,-41609056256,3875582805746,25008143335424,
%U A385140 -2601876338050582,-20048671462064128,2308957345471798978,20711293319504723968,-2618684079639256157974,-26823633677081126109184
%N A385140 E.g.f. A(x) satisfies A(x) = exp(2*x*A(-x)^(1/2)).
%F A385140 E.g.f.: B(x)^2, where B(x) is the e.g.f. of A141369.
%F A385140 a(n) = 2 * Sum_{k=0..n} (n-k+2)^(k-1) * (-k)^(n-k) * binomial(n,k).
%o A385140 (PARI) a(n) = 2*sum(k=0, n, (n-k+2)^(k-1)*(-k)^(n-k)*binomial(n, k));
%Y A385140 Cf. A141369, A385141.
%Y A385140 Cf. A360987.
%K A385140 sign
%O A385140 0,2
%A A385140 _Seiichi Manyama_, Jun 19 2025