Number of n-chains of divisors of n.

Terms

a(0) =1a(1) =3a(2) =4a(3) =15a(4) =6a(5) =49a(6) =8a(7) =165a(8) =55a(9) =121a(10) =12a(11) =1183a(12) =14a(13) =225a(14) =256a(15) =4845a(16) =18a(17) =3610a(18) =20a(19) =4851a(20) =484a(21) =529a(22) =24a(23) =73125a(24) =351a(25) =729a(26) =4060a(27) =12615a(28) =30a(29) =29791