OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
x=2032=16*127 has 4 unitary divisors: {1,16,127,2032} and ud[ x ]^2=16 divides 2032.
MATHEMATICA
Select[Range[10^3], Divisible[#, 4^PrimeNu[#]] &] (* Amiram Eldar, Aug 05 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved