a(n) = Sum_{k=0..n} binomial(5*n+k+2,n-k).
A390336
a(n) = Sum_{k=0..n} binomial(5*n+k+2,n-k).
Terms
- a(0) =1a(1) =8a(2) =80a(3) =853a(4) =9388a(5) =105326a(6) =1197117a(7) =13734865a(8) =158715688a(9) =1844434121a(10) =21532145438a(11) =252318496636
External references
- oeis: A390336