A075034 Numbers n such that tau(n) >= tau(n+1) >= tau(n+2) where tau(n) = number of divisors of n.

20, 21, 32, 33, 44, 45, 56, 57, 75, 80, 81, 84, 85, 92, 93, 104, 105, 116, 117, 132, 135, 140, 141, 144, 147, 165, 170, 171, 176, 177, 189, 200, 201, 204, 212, 213, 216, 217, 224, 225, 230, 231, 242, 243, 252, 260, 261, 272, 285, 296, 297, 300, 301, 315, 324

Offset

1,1

Links

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

Mathematica

nn = 400; t = DivisorSigma[0, Range[nn]]; Select[Range[nn-2], t[[#]] >= t[[#+1]] >= t[[#+2]] &] (* Harvey P. Dale, May 24 2012 *)

Prog

(Python)
from sympy import divisor_count as tau
[n for n in range(1, 333) if tau(n) >= tau(n+1) >= tau(n+2)] # Karl V. Keller, Jr., Jul 10 2020

Crossrefs

Cf. A000005 (tau), A075032, A075033, A075035.

Sequence in context: A118865 A118608 A176241 * A363770 A022110 A041808

Adjacent sequences: A075031 A075032 A075033 * A075035 A075036 A075037

Keyword

nonn

Author

Amarnath Murthy, Sep 02 2002

Extensions

More terms from Benoit Cloitre, Sep 07 2002

Status

approved