OFFSET
1,2
LINKS
Karl V. Keller, Jr., Table of n, a(n) for n = 1..10000
MATHEMATICA
With[{s = Partition[Differences@ Array[DivisorSigma[0, #] &, 800], 3, 1]}, Position[s, _?(AllTrue[#, # >= 0 &] &), {1}, Heads -> False][[All, 1]]] (* Michael De Vlieger, Jun 28 2020 *)
PROG
(Python)
from sympy import divisor_count as tau
[n for n in range(1, 801) if tau(n) <= tau(n+1) <= tau(n+2) <= tau(n+3)] # Karl V. Keller, Jr., Jul 10 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Sep 02 2002
EXTENSIONS
Added missing term and a(11)-a(54) from Donovan Johnson, Jun 15 2009
STATUS
approved