a(n) = 3*binomial(8*n+3,n)/(8*n+3).

A234462

a(n) = 3*binomial(8*n+3,n)/(8*n+3).

Terms

    a(0) =1a(1) =3a(2) =27a(3) =325a(4) =4488a(5) =67158a(6) =1059380a(7) =17346582a(8) =292046040a(9) =5023824887a(10) =87915626370

External references