a(n) = 7*binomial(8*n+7,n)/(8*n+7).

A234466

a(n) = 7*binomial(8*n+7,n)/(8*n+7).

Terms

    a(0) =1a(1) =7a(2) =77a(3) =1015a(4) =14763a(5) =228459a(6) =3689595a(7) =61474519a(8) =1048927880a(9) =18236463245a(10) =321899509386

External references