a(n) = 4 * binomial(7*n+4,n)/(7*n+4).

A386392

a(n) = 4 * binomial(7*n+4,n)/(7*n+4).

Terms

    a(0) =1a(1) =4a(2) =34a(3) =368a(4) =4495a(5) =59052a(6) =814506a(7) =11633440a(8) =170574723a(9) =2552698720a(10) =38832808586a(11) =598724403680

External references