a(n) = Sum_{k=0..n} 3^(n-k) * binomial(n+4,k+4) * binomial(2*k+8,k+8).
A387277
a(n) = Sum_{k=0..n} 3^(n-k) * binomial(n+4,k+4) * binomial(2*k+8,k+8).
Terms
- a(0) =1a(1) =25a(2) =381a(3) =4585a(4) =47978a(5) =458010a(6) =4100370a(7) =35027850a(8) =288845370a(9) =2317794050a(10) =18203687502a(11) =140533725150
External references
- oeis: A387277