a(n) = Sum_{k=0..n} 2^(n-k) * binomial(n+3,k+3) * binomial(2*k+6,k+6).

A387273

a(n) = Sum_{k=0..n} 2^(n-k) * binomial(n+3,k+3) * binomial(2*k+6,k+6).

Terms

    a(0) =1a(1) =16a(2) =165a(3) =1400a(4) =10661a(5) =75936a(6) =517524a(7) =3420960a(8) =22123530a(9) =140782048a(10) =885008839a(11) =5511579528a(12) =34073731965a(13) =209428887360

External references