OFFSET
1,1
MAPLE
with(numtheory): [seq(`if`(sigma(i) mod i <> 0, i, print( )), i=1..90)];
MATHEMATICA
Select[Range[100], !Divisible[DivisorSigma[1, #], #]&] (* Harvey P. Dale, May 29 2019 *)
PROG
(PARI) isok(m) = (sigma(m) % m) != 0; \\ Michel Marcus, Jun 20 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Asher Auel, Jan 19 2000
STATUS
approved