a(n) = (1/2) * (3*n)! / n!^3 for n > 0, a(0) = 1.

A386876

a(n) = (1/2) * (3*n)! / n!^3 for n > 0, a(0) = 1.

Terms

    a(0) =1a(1) =3a(2) =45a(3) =840a(4) =17325a(5) =378378a(6) =8576568a(7) =199536480a(8) =4732755885a(9) =113936715750

External references