a(n) = binomial(2^n + 3*n, n).A132688a(n) = binomial(2^n + 3*n, n).Terms a(0) =1a(1) =5a(2) =45a(3) =680a(4) =20475a(5) =1533939a(6) =350161812a(7) =280384608504External referencesoeis: A132688