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 A334284 #4 Apr 21 2020 19:07:24
%S A334284 1,1,2,4,8,8,16,64,128,64,256,512,1024,2048,2048,16384,32768,16384,
%T A334284 65536,131072,262144,262144,524288,2097152,4194304,2097152,8388608,
%U A334284 8388608,16777216,134217728,67108864,1073741824,2147483648,1073741824,4294967296
%N A334284 Denominators of power series coefficients of A(x) satisfying A(A(x)) = x + Sum_{k>=2} prime(k-1) * x^k.
%H A334284 Wikipedia, <a href="https://en.wikipedia.org/wiki/Functional_square_root">Functional square root</a>
%e A334284 1, 1, 1/2, 3/4, -3/8, 11/8, -47/16, 291/64, -361/128, -327/64, 2651/256, 8117/512, -23761/1024, -920509/2048, ...
%Y A334284 Cf. A008578, A030275, A030278, A334283 (numerators).
%K A334284 nonn,frac
%O A334284 1,3
%A A334284 _Ilya Gutkovskiy_, Apr 21 2020