Expansion of g.f. Product_{k>=1} 1/(1-x^sigma(k)).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =3a(6) =5a(7) =7a(8) =9a(9) =11a(10) =14a(11) =17a(12) =24a(13) =29a(14) =36a(15) =46a(16) =57a(17) =66a(18) =85a(19) =103a(20) =125a(21) =151a(22) =182a(23) =213a(24) =264a(25) =310a(26) =368a(27) =440a(28) =524a(29) =604