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 A376061 #11 Sep 15 2024 17:45:12
%S A376061 2,6,78,30498,13021822554,7121850230383271305026,
%T A376061 6695139092929353602428277531338786356808914258
%N A376061 a(n) is the denominator of the sum S(n) defined in A376060.
%F A376061 a(n+1) = Catalan(n+1)*a(n)^2 + a(n), with a(0) = 2.
%e A376061 The first few values of S(n) are 1/2, 5/6, 77/78, 30497/30498, 13021822553/13021822554, ...
%t A376061 RecurrenceTable[{a[n+1] == CatalanNumber[n+1]*a[n]^2 + a[n], a[0] == 2}, a, {n, 0, 6}] (* _Amiram Eldar_, Sep 15 2024 *)
%Y A376061 Cf. A000108, A374663, A375516, A375531, A375532, A375781, A375522, A376048-A376060.
%K A376061 nonn,base,frac
%O A376061 0,1
%A A376061 _N. J. A. Sloane_, Sep 14 2024