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 A363655 #6 Jul 21 2023 16:06:12
%S A363655 1,2,7,61,863,17569,472741,16007419,659408567,32231133931,
%T A363655 1833425773489,119498316410171,8810846732918257,727089137774221667
%N A363655 a(0) = 1; for n > 0, a(n) = prime( Sum_{k=0..n-1} a(k) * a(n-k-1) ).
%F A363655 G.f.: sqrt( Sum_{n>=0} index of prime a(n+1) * x^n ).
%t A363655 a[0] = 1; a[n_] := a[n] = Prime[Sum[a[k] a[n - k - 1], {k, 0, n - 1}]]; Table[a[n], {n, 0, 11}]
%Y A363655 Cf. A000040, A000108, A014342, A007097, A093502, A338816.
%K A363655 nonn,hard,more
%O A363655 0,2
%A A363655 _Ilya Gutkovskiy_, Jun 13 2023
%E A363655 a(12)-a(13) from _Amiram Eldar_, Jun 13 2023