OFFSET
1,2
COMMENTS
LINKS
Ivan Neretin, Table of n, a(n) for n = 1..10000
EXAMPLE
Number 24 is in sequence because gcd(24, sigma(24)) = (sigma(24)=60) mod 24 = 12.
MATHEMATICA
Select[Range[300], Mod[GCD[#, DivisorSigma[1, #]] - DivisorSigma[1, #], #] == 0 &]
PROG
(PARI) isok(n) = (gcd(n, sigma(n)) % n) == (sigma(n) % n); \\ Michel Marcus, Dec 22 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Jan 28 2012
EXTENSIONS
Corrected by T. D. Noe, Feb 03 2012
STATUS
approved