a(n) = Sum_{k=0..n} (-1)^k * binomial(5*n-k+3,n-k).
A390590
a(n) = Sum_{k=0..n} (-1)^k * binomial(5*n-k+3,n-k).
Terms
- a(0) =1a(1) =7a(2) =67a(3) =695a(4) =7506a(5) =83053a(6) =933976a(7) =10625591a(8) =121943011a(9) =1409002062a(10) =16369338514a(11) =191024179421
External references
- oeis: A390590