OFFSET
0,4
LINKS
Ray Chandler, Table of n, a(n) for n = 0..1000
EXAMPLE
For n=3, sigma(1,k) = 6^3 = 216 for each of 5 integers: 102, 110, 142, 159, and 187, so a(3) = 5.
MATHEMATICA
With[{s = Array[DivisorSigma[1, #] &, 6^8]}, Array[Count[s, 6^#] &, Log[6, Length@ s] + 1, 0]] (* Michael De Vlieger, May 14 2018 *)
PROG
(PARI) a(n) = sum(k=1, 6^n, sigma(k)==6^n); \\ Michel Marcus, May 14 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
a(9)-a(14) from Donovan Johnson, Sep 02 2008
Edited and extended by Ray Chandler, Sep 01 2010
STATUS
approved