a(n) = 9*binomial(11*n+9,n)/(11*n+9).

A235339

a(n) = 9*binomial(11*n+9,n)/(11*n+9).

Terms

    a(0) =1a(1) =9a(2) =135a(3) =2460a(4) =49725a(5) =1072197a(6) =24163146a(7) =562311720a(8) =13409091540a(9) =325949656825

External references