A075032 Numbers n such that tau(n) <= tau(n+1) <= tau(n+2) where tau(n) = number of divisors of n.

1, 2, 13, 14, 25, 26, 33, 34, 37, 38, 43, 61, 62, 73, 74, 85, 86, 93, 94, 97, 98, 103, 115, 118, 121, 122, 133, 134, 141, 142, 145, 146, 157, 158, 163, 187, 188, 193, 194, 201, 202, 205, 206, 213, 214, 217, 218, 229, 230, 241, 242, 243, 244, 253, 254, 274, 277

Offset: 1

Author

Amarnath Murthy, Sep 02 2002

Keywords

• nonn

Links

• Karl V. Keller, Jr., Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000005, A075033, A075034, A075035, A005238 (subsequence).

Programs

Python

from sympy import divisor_count as tau
[n for n in range(1,303) if tau(n) <= tau(n+1) <= tau(n+2)] # Karl V. Keller, Jr., Jul 10 2020

Extensions

Corrected and extended by Benoit Cloitre, Sep 07 2002