a(n) = binomial(3*prime(n), prime(n)) - 3*binomial(2*prime(n), prime(n)) + 3.

A272630

a(n) = binomial(3*prime(n), prime(n)) - 3*binomial(2*prime(n), prime(n)) + 3.

Terms

    a(0) =0a(1) =27a(2) =2250a(3) =105987a(4) =191420427a(5) =8091223647

External references