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 A386298 #7 Jul 18 2025 08:30:15
%S A386298 1,2,7,52,721,17594,754063,58139188,8321310193,2272187953346,
%T A386298 1206524396886823,1260788083530821380,2611061273843639666401,
%U A386298 10760136322351992470924570,88437432027319862460463145551,1451522912694521425631922482171812,47608493474799808182534348919785356065
%N A386298 a(n) = 1 + Sum_{k=0..n-1} 2^k * binomial(n-1,k) * a(k) * a(n-1-k).
%F A386298 E.g.f. A(x) satisfies A'(x) = exp(x) + A(x) * A(2*x).
%o A386298 (PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=1+sum(j=0, i-1, 2^j*binomial(i-1, j)*v[j+1]*v[i-j])); v;
%Y A386298 Cf. A054687, A386299, A386300.
%Y A386298 Cf. A345104, A348857.
%K A386298 nonn
%O A386298 0,2
%A A386298 _Seiichi Manyama_, Jul 17 2025