a(n) = (2*n+9)!!/9!!, related to A001147 (odd double factorials).

A051583

a(n) = (2*n+9)!!/9!!, related to A001147 (odd double factorials).

Terms

    a(0) =1a(1) =11a(2) =143a(3) =2145a(4) =36465a(5) =692835a(6) =14549535a(7) =334639305a(8) =8365982625a(9) =225881530875

External references