OFFSET
1,1
COMMENTS
Numbers with a unitary divisor of the form p^(m*p) where p is a prime and m > 0.
The numbers of terms that do not exceed 10^k, for k = 1, 2, ..., are 1, 19, 188, 1883, 18825, 188244, 1882429, 18824297, 188242957, 1882429628, ...
The asymptotic density of this sequence is 1 - Product_{p prime} 1 - (p - 1)/(p*(p^p - 1)) = 0.18824296270011399086...
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
4 = 2^2 is a term since 2 divides 2.
8 = 2^3 is not a term since 2 does not divide 3.
MATHEMATICA
q[n_] := AnyTrue[FactorInteger[n], Divisible[Last[#], First[#]] &]; Select[Range[2, 300], q]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Feb 27 2021
EXTENSIONS
Wrong term 1 removed by Amiram Eldar, Jan 16 2024
STATUS
approved