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 A246604 #12 Sep 08 2022 08:46:09
%S A246604 1,0,0,2,10,37,126,422,1422,4853,16786,58775,208000,742887,2674426,
%T A246604 9694830,35357654,129644773,477638682,1767263171,6564120400,
%U A246604 24466266999,91482563618,343059613627,1289904147300,4861946401427,18367353072126,69533550915977,263747951750332,1002242216651339
%N A246604 a(n) = Catalan(n) - n.
%H A246604 Vincenzo Librandi, <a href="/A246604/b246604.txt">Table of n, a(n) for n = 0..1000</a>
%t A246604 Table[(CatalanNumber[n] - n), {n, 0, 20}]
%o A246604 (Magma) [Catalan(n)-n: n in [0..30]];
%Y A246604 Cf. A000108, A024483, A246574.
%Y A246604 All of A000108, A001453, A246604, A273526, A120304, A289615, A289616, A289652, A289653, A289654 are very similar sequences.
%K A246604 nonn
%O A246604 0,4
%A A246604 _Vincenzo Librandi_, Aug 31 2014