OFFSET
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..100
Jean-Marie de Koninck, Florian Luca, Integers divisible by sums of powers of their prime factors, Journal of Number Theory, Volume 128, Issue 3, March 2008, Pages 557-563.
PROG
(PARI) isok(n) = my(f = factor(n)[, 1]); (#f>2) && ((n % vecsum(f)) == 0) && ((n % sum(k=1, #f, f[k]^2)) == 0) && ((n % sum(k=1, #f, f[k]^3)) == 0);
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Feb 04 2016
STATUS
approved