G.f.: exp( Sum_{n>=1} 2*sigma(n*4^n)*x^n/n ).

A193103

G.f.: exp( Sum_{n>=1} 2*sigma(n*4^n)*x^n/n ).

Terms

    a(0) =1a(1) =14a(2) =161a(3) =1678a(4) =15524a(5) =134844a(6) =1113797a(7) =8791370a(8) =66966377a(9) =495285252a(10) =3566916109a(11) =25105766336a(12) =173194384597

External references