a(n) = Sum_{k=0..n} binomial(4*n+k,n-k).

A389361

a(n) = Sum_{k=0..n} binomial(4*n+k,n-k).

Terms

    a(0) =1a(1) =5a(2) =38a(3) =313a(4) =2673a(5) =23307a(6) =206009a(7) =1838554a(8) =16527302a(9) =149405885a(10) =1356719781a(11) =12365705324a(12) =113055426671

External references