G.f.: A(q) = exp( Sum_{n>=1} sigma(n) * 3*A038500(n) * q^n/n ), where A038500(n) = highest power of 3 dividing n.

A163129

G.f.: A(q) = exp( Sum_{n>=1} sigma(n) * 3*A038500(n) * q^n/n ), where A038500(n) = highest power of 3 dividing n.

Terms

    a(0) =1a(1) =3a(2) =9a(3) =30a(4) =75a(5) =180a(6) =441a(7) =969a(8) =2070a(9) =4431a(10) =8964a(11) =17775a(12) =35094a(13) =66975a(14) =125865a(15) =235053a(16) =429096a(17) =773766a(18) =1386027a(19) =2442372a(20) =4260645a(21) =7384578a(22) =12640320a(23) =21453975a(24) =36192519a(25) =60454713a(26) =100250100a(27) =165311094a(28) =270391857a(29) =439479198

External references