a(n) = Sum_{k=0..n-1} binomial(5*k-1,k) * binomial(5*n-5*k,n-k-1).
A386566
a(n) = Sum_{k=0..n-1} binomial(5*k-1,k) * binomial(5*n-5*k,n-k-1).
Terms
- a(0) =0a(1) =1a(2) =14a(3) =181a(4) =2284a(5) =28506a(6) =353630a(7) =4370584a(8) =53882392a(9) =663116347a(10) =8150224204a(11) =100073884670
External references
- oeis: A386566