Sum of numbers of ways to choose a k-chain of divisors of n - k, for k = 0..n - 1.

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =12a(5) =19a(6) =30a(7) =45a(8) =66a(9) =95a(10) =135a(11) =187a(12) =256a(13) =346a(14) =463a(15) =613a(16) =803a(17) =1040a(18) =1336a(19) =1703a(20) =2158a(21) =2720a(22) =3409a(23) =4244a(24) =5251a(25) =6461a(26) =7911a(27) =9643a(28) =11707a(29) =14157