a(n) = [x^n] Product_{k>=1} (1 + x^k)^sigma_n(k).

A321042

a(n) = [x^n] Product_{k>=1} (1 + x^k)^sigma_n(k).

Terms

    a(0) =1a(1) =1a(2) =5a(3) =37a(4) =491a(5) =12763a(6) =690756a(7) =70250881a(8) =13805853214

External references