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A347202
Numbers whose number of odd divisors is not equal to 2.
0
1, 2, 4, 8, 9, 15, 16, 18, 21, 25, 27, 30, 32, 33, 35, 36, 39, 42, 45, 49, 50, 51, 54, 55, 57, 60, 63, 64, 65, 66, 69, 70, 72, 75, 77, 78, 81, 84, 85, 87, 90, 91, 93, 95, 98, 99, 100, 102, 105, 108, 110, 111, 114, 115, 117, 119, 120, 121, 123, 125, 126, 128, 129, 130
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
Members of A266531 (sorted), except the column 2.
Cf. A001227, A038550 (complement), A237593, A279387 (subparts).
Sequence in context: A048300 A178953 A182653 * A036349 A352827 A364290
KEYWORD
nonn
AUTHOR
Omar E. Pol, Aug 22 2021
STATUS
approved