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 A385648 #10 Jul 06 2025 10:39:39
%S A385648 1,4,64,1872,91328,7563648,1115422976,306988895488,162926170881024,
%T A385648 169827391985854464,350891899856754294784,1443597302250006622052352,
%U A385648 11851990053153536620868173824,194396568906445310993071164686336,6373487768490075927307409156798611456
%N A385648 G.f. A(x) satisfies A(x) = 1/( 1 - x*(A(x) + A(2*x))^2 ).
%F A385648 a(0) = 1; a(n) = Sum_{i, j, k>=0 and i+j+k=n-1} (2^j+1) * (2^k+1) * a(i) * a(j) * a(k).
%Y A385648 Cf. A385617, A385649.
%Y A385648 Cf. A171192, A385650.
%K A385648 nonn
%O A385648 0,2
%A A385648 _Seiichi Manyama_, Jul 06 2025