Reversion of Moebius function A008683.

Terms

a(0) =1a(1) =1a(2) =3a(3) =10a(4) =39a(5) =160a(6) =691a(7) =3081a(8) =14095a(9) =65757a(10) =311695a(11) =1496833a(12) =7266979a(13) =35608419a(14) =175875537a(15) =874698246a(16) =4376646808a(17) =22016578909a(18) =111282845162a(19) =564886771380