a(n) = (7^n/n!^2) * Product_{k=0..n-1} (14k+3)*(14k+4).

A185403

a(n) = (7^n/n!^2) * Product_{k=0..n-1} (14k+3)*(14k+4).

Terms

    a(0) =1a(1) =84a(2) =44982a(3) =34706112a(4) =31430722680

External references