a(n) = binomial(6*n,n)*(4*n+1)/(5*n+1).

A215542

a(n) = binomial(6*n,n)*(4*n+1)/(5*n+1).

Terms

    a(0) =1a(1) =5a(2) =54a(3) =663a(4) =8602a(5) =115101a(6) =1570800a(7) =21732542a(8) =303719922a(9) =4277470470a(10) =60610884906a(11) =863102246760

External references