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 A382040 #11 Mar 13 2025 09:51:59
%S A382040 1,1,12,198,4912,163120,6796224,341366704,20088997632,1356164492544,
%T A382040 103333898644480,8773563043734016,821474949840482304,
%U A382040 84093840447771701248,9344359942839980900352,1120159940123276849141760,144096985208727744665288704,19800296439825918648654561280
%N A382040 Expansion of e.g.f. (1/x) * Series_Reversion( x*(1 - x*exp(4*x)) ).
%F A382040 E.g.f. A(x) satisfies A(x) = 1 + x*A(x)^2*exp(4*x*A(x)).
%F A382040 a(n) = (1/(n+1)) * Sum_{k=0..n} (4*k)^(n-k) * (n+k)!/(k! * (n-k)!).
%o A382040 (PARI) a(n) = sum(k=0, n, (4*k)^(n-k)*(n+k)!/(k!*(n-k)!))/(n+1);
%Y A382040 Cf. A213644, A379690, A382039.
%Y A382040 Cf. A366234, A382031.
%K A382040 nonn
%O A382040 0,3
%A A382040 _Seiichi Manyama_, Mar 13 2025