Number of coprime chains with largest member n.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =1a(6) =3a(7) =1a(8) =3a(9) =2a(10) =9a(11) =1a(12) =10a(13) =2a(14) =4a(15) =3a(16) =19a(17) =1a(18) =20a(19) =2a(20) =6a(21) =4a(22) =32a(23) =1a(24) =21a(25) =7a(26) =16a(27) =7a(28) =84a(29) =1