a(n) = Sum_{k=0..n} 2^k * 3^(n-k) * binomial(n+2,k) * binomial(n+2,n-k).
A387369
a(n) = Sum_{k=0..n} 2^k * 3^(n-k) * binomial(n+2,k) * binomial(n+2,n-k).
Terms
- a(0) =1a(1) =15a(2) =174a(3) =1850a(4) =18915a(5) =189525a(6) =1877596a(7) =18476820a(8) =181083285a(9) =1770245675a(10) =17278828842a(11) =168496597230
External references
- oeis: A387369