a(n) = Sum_{k=0..n} 2^k * binomial(n+3,k) * binomial(n+3,k+3).
A387338
a(n) = Sum_{k=0..n} 2^k * binomial(n+3,k) * binomial(n+3,k+3).
Terms
- a(0) =1a(1) =12a(2) =100a(3) =720a(4) =4809a(5) =30744a(6) =191184a(7) =1167120a(8) =7033785a(9) =41999364a(10) =249075684a(11) =1469561184a(12) =8636441905a(13) =50600529840a(14) =295755641152
External references
- oeis: A387338