a(n) = C(5*n-1,2*n)/3, n > 0, a(0) = 1.

A259550

a(n) = C(5*n-1,2*n)/3, n > 0, a(0) = 1.

Terms

    a(0) =1a(1) =2a(2) =42a(3) =1001a(4) =25194a(5) =653752a(6) =17298645a(7) =463991880a(8) =12570420330a(9) =343176898988

External references