a(n) = [x^n] 1/(1 - x) * Legendre_P(n, (1 + x)/(1 - x))^n for n >= 0.

A364116

a(n) = [x^n] 1/(1 - x) * Legendre_P(n, (1 + x)/(1 - x))^n for n >= 0.

Terms

    a(0) =1a(1) =3a(2) =73a(3) =5623a(4) =908001a(5) =251831261a(6) =106898093065

External references