a(n) = Sum_{k=0..n} (-1)^k * (k+1) * binomial(5*n-4*k+1,n-k)/(5*n-4*k+1).
A390741
a(n) = Sum_{k=0..n} (-1)^k * (k+1) * binomial(5*n-4*k+1,n-k)/(5*n-4*k+1).
Terms
- a(0) =1a(1) =0a(2) =4a(3) =26a(4) =220a(5) =1979a(6) =18752a(7) =184248a(8) =1860440a(9) =19188713a(10) =201300641a(11) =2141257456a(12) =23041395524a(13) =250374248123
External references
- oeis: A390741