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 A349603 #17 Nov 23 2021 09:44:30
%S A349603 1,1,4,20,126,937,7938,74909,775022,8688827,104608026,1342844846,
%T A349603 18273663268,262347913479,3957524475778,62511713866200,
%U A349603 1030842278673510,17700339693712731,315740112103311666,5839137279831300536,111749137533005481700,2209538389126578658875
%N A349603 a(n) = Sum_{k=0..n} binomial(n,k) * A000108(k) * k^(n-k).
%t A349603 Join[{1}, Table[Sum[Binomial[n, j]*CatalanNumber[j]*j^(n-j), {j, 0, n}], {n, 1, 25}]]
%o A349603 (PARI) a(n) = sum(k=0, n, binomial(n,k)*(binomial(2*k,k)/(k+1))*k^(n-k)); \\ _Michel Marcus_, Nov 23 2021
%Y A349603 Cf. A000248, A007317, A064613, A104455, A104498, A154623, A292632.
%K A349603 nonn
%O A349603 0,3
%A A349603 _Vaclav Kotesovec_, Nov 23 2021