Expansion of Product_{k>=1} (1 + 3^(k+1)*x^k) * (1 + 3^(k-1)*x^k).

A370792

Expansion of Product_{k>=1} (1 + 3^(k+1)*x^k) * (1 + 3^(k-1)*x^k).

Terms

    a(0) =1a(1) =10a(2) =39a(3) =390a(4) =1521a(5) =7830a(6) =49518a(7) =207360a(8) =951102a(9) =4264650a(10) =22185657a(11) =89579520a(12) =401428224a(13) =1676401110a(14) =7172977275a(15) =31972081050a(16) =130330236546a(17) =537393139200

External references