a(n) = 2^n * [x^n] Product_{k>=1} ((1 + 3*x^k)/(1 - 3*x^k))^(1/2).

A370751

a(n) = 2^n * [x^n] Product_{k>=1} ((1 + 3*x^k)/(1 - 3*x^k))^(1/2).

Terms

    a(0) =1a(1) =6a(2) =30a(3) =204a(4) =966a(5) =5748a(6) =29388a(7) =169944a(8) =886278a(9) =5169732a(10) =27794820a(11) =162920616a(12) =894445212a(13) =5274022920a(14) =29398573272a(15) =174041671344a(16) =980746798278

External references