a(n) = Sum_{k=0..n} (n+k+3)!/((n-k)!*k!*2^k).

A144514

a(n) = Sum_{k=0..n} (n+k+3)!/((n-k)!*k!*2^k).

Terms

    a(0) =6a(1) =84a(2) =1050a(3) =13980a(4) =205800a(5) =3368316a(6) =61075854a(7) =1219445100a(8) =26635157010a(9) =632479986600

External references