a(n) = Sum_{k=0..n} 3^(n-k) * binomial(n,k) * binomial(n+3,k).
A388410
a(n) = Sum_{k=0..n} 3^(n-k) * binomial(n,k) * binomial(n+3,k).
Terms
- a(0) =1a(1) =7a(2) =49a(3) =344a(4) =2426a(5) =17189a(6) =122313a(7) =873660a(8) =6261150a(9) =45001390a(10) =324266842a(11) =2341813984a(12) =16945884500a(13) =122841115505a(14) =891888498425
External references
- oeis: A388410