A193672 Numbers such that the last of the differences of divisors is < 0.

14, 20, 22, 24, 26, 28, 34, 36, 38, 40, 46, 48, 50, 58, 60, 62, 63, 70, 74, 80, 82, 84, 86, 94, 96, 98, 99, 100, 105, 106, 117, 118, 120, 122, 134, 136, 138, 140, 142, 146, 152, 153, 154, 158, 160, 166, 170, 174, 178, 180, 182, 184, 186, 189, 190, 192, 194

Offset: 1

Author

Reinhard Zumkeller, Aug 02 2011

Keywords

• nonn

Comments

A187202(a(n)) < 0.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A187204, A193672.

Programs

Haskell

import Data.List (findIndices)
a193672 n = a193672_list !! (n-1)
a193672_list = map (+ 1) $ findIndices (< 0) $ map a187202 [1..]

Mathematica

Select[Range[200],Differences[Divisors[#],DivisorSigma[0,#]-1][[1]]<0&] (* Harvey P. Dale, Feb 14 2025 *)