Generating function exp( sum(n>=1, sigma(n)^3*x^n/n ) ).

Terms

a(0) =1a(1) =1a(2) =14a(3) =35a(4) =205a(5) =521a(6) =2507a(7) =6709a(8) =26712a(9) =73834a(10) =262431a(11) =724537a(12) =2384988a(13) =6552033a(14) =20289864a(15) =55244988a(16) =163342701a(17) =439201501a(18) =1251532060a(19) =3321188863a(20) =9177476977a(21) =24028568664a(22) =64709650590a(23) =167153761523a(24) =440300702427