G.f.: exp( Sum_{n>=1} (x^n/n) / Product_{d|n} (1 - d*x^n)^d ).

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =7a(5) =9a(6) =26a(7) =32a(8) =85a(9) =129a(10) =293a(11) =389a(12) =1105a(13) =1426a(14) =3242a(15) =5121a(16) =11405a(17) =15790a(18) =37704a(19) =52289a(20) =118470a(21) =181770a(22) =373257a(23) =543137a(24) =1250814a(25) =1796474a(26) =3713201a(27) =5790866a(28) =11919993a(29) =17663189