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 A371296 #8 Mar 18 2024 11:46:37 %S A371296 1,2,26,674,26682,1429682,96867178,7946279490,765861255002, %T A371296 84837503946962,10621798904563530,1483378875680954210, %U A371296 228626616449674796602,38549099486166110798322,7058696888173770772536362,1394913467379909728350803074,295904373562519633314958421274 %N A371296 E.g.f. satisfies A(x) = 1/(3 - 2*exp(x*A(x)^2)). %F A371296 a(n) = (1/(2*n+1)!) * Sum_{k=0..n} 2^k * (2*n+k)! * Stirling2(n,k). %o A371296 (PARI) a(n) = sum(k=0, n, 2^k*(2*n+k)!*stirling(n, k, 2))/(2*n+1)!; %Y A371296 Cf. A004123, A258922. %Y A371296 Cf. A367134. %K A371296 nonn %O A371296 0,2 %A A371296 _Seiichi Manyama_, Mar 18 2024