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

Terms

a(0) =1a(1) =3a(2) =4a(3) =15a(4) =6a(5) =78a(6) =8a(7) =247a(8) =202a(9) =708a(10) =12a(11) =4146a(12) =14a(13) =5498a(14) =8964a(15) =24135a(16) =18a(17) =81114a(18) =20a(19) =206520a(20) =193736a(21) =225558a(22) =24a(23) =2314378a(24) =242656a(25) =1278332a(26) =3622954a(27) =9209950a(28) =30a(29) =26654118