OFFSET
1,4
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = A048105(n!). - Michel Marcus, Jun 30 2017
EXAMPLE
n=5, 5!=120 has 16 divisors of which 8 are not unitary:{2,60,4,30,6,20,10,12} while {1,120,3,40,5,24,15,16} are the unitary ones.
MATHEMATICA
Table[Function[k, DivisorSum[k, 1 &, ! CoprimeQ[#, k/#] &]][n!], {n, 30}] (* Michael De Vlieger, Jun 29 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved