a(n) = Sum_{k=0..n} 3^(n-k) * binomial(n+1,k+1) * binomial(2*k+2,k+2).
A387278
a(n) = Sum_{k=0..n} 3^(n-k) * binomial(n+1,k+1) * binomial(2*k+2,k+2).
Terms
- a(0) =1a(1) =10a(2) =78a(3) =560a(4) =3885a(5) =26550a(6) =180285a(7) =1221400a(8) =8272251a(9) =56062550a(10) =380361212a(11) =2583867720a(12) =17575724491a(13) =119705522370a(14) =816297170310
External references
- oeis: A387278