a(n) = 7*binomial(10*n+7,n)/(10*n+7).

A234570

a(n) = 7*binomial(10*n+7,n)/(10*n+7).

Terms

    a(0) =1a(1) =7a(2) =91a(3) =1470a(4) =26565a(5) =514206a(6) =10426416a(7) =218618940a(8) =4701550770a(9) =103134123820

External references