|
|
A046754
|
|
Numbers k such that the square of d(k) (number of divisors) divides k.
|
|
7
|
|
|
1, 9, 128, 625, 972, 1152, 2000, 2025, 5625, 6561, 7776, 8100, 10000, 10800, 18000, 21952, 26244, 30000, 32768, 35721, 50625, 55296, 56700, 64000, 64800, 65856, 70000, 80000, 84672, 89100, 90000, 97200, 98304, 99225, 105300, 109760, 110000
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
If k = 972, d(k) = sigma(0,k) = 18. Its square is 324 which divides 972.
|
|
MATHEMATICA
|
Select[Range[110000], IntegerQ[#/DivisorSigma[0, #]^2] &] (* Jayanta Basu, Jun 28 2013 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|