a(n) = 7*binomial(9*n+7,n)/(9*n+7).

A234510

a(n) = 7*binomial(9*n+7,n)/(9*n+7).

Terms

    a(0) =1a(1) =7a(2) =84a(3) =1232a(4) =20090a(5) =349860a(6) =6371764a(7) =119877472a(8) =2311664355a(9) =45448324110a(10) =907580289616

External references