OFFSET
1,2
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..1000
EXAMPLE
sigma(30) - phi(30) = 72 - 8 = 64 = 4^3, so 30 is a term of the sequence.
MATHEMATICA
Select[Range[10^4], IntegerQ[(DivisorSigma[1, # ] - EulerPhi[ # ])^(1/3)] &]
PROG
(PARI) select(k->ispower(sigma(k)-eulerphi(k), 3), [1..10000]) \\ Harry J. Smith, Aug 06 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Joseph L. Pe, Feb 13 2002
STATUS
approved