a(n) = Sum_{k=0..floor(n/3)} binomial(5*n-2*k,n-3*k).
A371756
a(n) = Sum_{k=0..floor(n/3)} binomial(5*n-2*k,n-3*k).
Terms
- a(0) =1a(1) =5a(2) =45a(3) =456a(4) =4863a(5) =53383a(6) =597052a(7) =6765471a(8) =77407257a(9) =892270250a(10) =10346070471a(11) =120542238796
External references
- oeis: A371756