OFFSET
1,2
COMMENTS
Numbers that are not products of an odd prime and a power of 2.
Numbers k such that the symmetric representation of sigma(k) has a number of subparts not equal to 2.
PROG
(PARI) isok(m) = sumdiv(m, d, d%2) != 2; \\ Michel Marcus, Aug 23 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Aug 22 2021
STATUS
approved