L.g.f.: Sum_{n>=1} a(n)*x^n/n = Sum_{n>=1} x^n/n * exp( Sum_{k>=1} a(k)*x^(n*k)/k ).

Terms

a(0) =1a(1) =3a(2) =7a(3) =19a(4) =46a(5) =129a(6) =337a(7) =939a(8) =2581a(9) =7238a(10) =20263a(11) =57337a(12) =162319a(13) =461961a(14) =1317217a(15) =3767035a(16) =10792400a(17) =30983565a(18) =89084845a(19) =256531814a(20) =739658815a(21) =2135234247a(22) =6170505666a(23) =17849457873a(24) =51679366171a(25) =149750711581a(26) =434260829464