G.f.: A(x) = exp( Sum_{n>=1} sigma(n^3)*x^n/n ), a power series in x with integer coefficients.
A156304
G.f.: A(x) = exp( Sum_{n>=1} sigma(n^3)*x^n/n ), a power series in x with integer coefficients.
Terms
- a(0) =1a(1) =1a(2) =8a(3) =21a(4) =77a(5) =199a(6) =661a(7) =1663a(8) =4852a(9) =12382a(10) =33289a(11) =82877a(12) =213026a(13) =518109a(14) =1279852a(15) =3053404a(16) =7312985a(17) =17093793a(18) =39952528a(19) =91661695a(20) =209709116a(21) =473095589a(22) =1062567288a(23) =2359804486a(24) =5214774263a(25) =11415904502a(26) =24860918943a(27) =53709881911
External references
- oeis: A156304