a(0)=1, a(n) = a(n-1) - Sum_{k=2..n} mu(k) * a(n-k), where mu(k) is the Moebius function of k.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =7a(5) =14a(6) =25a(7) =48a(8) =90a(9) =168a(10) =316a(11) =592a(12) =1112a(13) =2086a(14) =3913a(15) =7342a(16) =13775a(17) =25845a(18) =48490a(19) =90978a(20) =170694a(21) =320257a(22) =600867a(23) =1127352a(24) =2115147a(25) =3968453a(26) =7445640a(27) =13969562a(28) =26209794a(29) =49175002