a(n) = A356500(2*n, 2*n+1) for n >= 0.

A356504

a(n) = A356500(2*n, 2*n+1) for n >= 0.

Terms

    a(0) =1a(1) =4a(2) =84a(3) =2568a(4) =94390a(5) =3863496a(6) =169713208a(7) =7836945872a(8) =375608185758

External references