a(n) = Sum_{k=0..n} 2^k * binomial(n+3,k+3) * binomial(2*k+6,k+6).
A387308
a(n) = Sum_{k=0..n} 2^k * binomial(n+3,k+3) * binomial(2*k+6,k+6).
Terms
- a(0) =1a(1) =20a(2) =270a(3) =3100a(4) =32711a(5) =328440a(6) =3195276a(7) =30433800a(8) =285604605a(9) =2651696300a(10) =24425110138a(11) =223636254660
External references
- oeis: A387308