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 A379856 #24 Jan 06 2025 04:22:55
%S A379856 1,0,1,-7,81,-1181,21373,-462267,11663137,-336711385,10955316501,
%T A379856 -396815693759,15840688752529,-691086583866069,32717602050027469,
%U A379856 -1670649590632148611,91530694441643402817,-5355984871255569700913,333392838283336197688741
%N A379856 E.g.f. A(x) satisfies A(x) = exp(-x*A(x)^2) + x.
%F A379856 a(n) = n! * Sum_{k=0..n} (-2*n+3*k-1)^(n-k) * binomial(2*n-2*k+1,k)/( (2*n-2*k+1)*(n-k)! ).
%o A379856 (PARI) a(n) = n!*sum(k=0, n, (-2*n+3*k-1)^(n-k)*binomial(2*n-2*k+1, k)/((2*n-2*k+1)*(n-k)!));
%Y A379856 Cf. A379868, A379877, A379909.
%Y A379856 Cf. A379858, A379875.
%K A379856 sign
%O A379856 0,4
%A A379856 _Seiichi Manyama_, Jan 05 2025