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 A331050 Positive integers whose number of factorizations into factors > 1 (A001055) is odd. 9
 1, 2, 3, 5, 7, 8, 11, 13, 16, 17, 19, 23, 24, 27, 29, 30, 31, 32, 36, 37, 40, 41, 42, 43, 47, 53, 54, 56, 59, 60, 61, 64, 66, 67, 70, 71, 73, 78, 79, 81, 83, 84, 88, 89, 90, 96, 97, 100, 101, 102, 103, 104, 105, 107, 109, 110, 113, 114, 120, 125, 126, 127, 128 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS First differs from A319239 in lacking 256. LINKS MATHEMATICA facs[n_]:=If[n<=1, {{}}, Join@@Table[Map[Prepend[#, d]&, Select[facs[n/d], Min@@#>=d&]], {d, Rest[Divisors[n]]}]]; Select[Range[100], OddQ[Length[facs[#]]]&] CROSSREFS Complement of A331051. The version for powers of two (instead of odds) is A330977. The version for primes (instead of odds) is A330991. Cf. A001055, A001221, A001222, A002033, A005117, A045778, A045782, A045783, A330972, A330973. Sequence in context: A287893 A051600 A319239 * A026410 A066720 A079851 Adjacent sequences:  A331047 A331048 A331049 * A331051 A331052 A331053 KEYWORD nonn AUTHOR Gus Wiseman, Jan 10 2020 STATUS approved

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Last modified August 7 12:19 EDT 2020. Contains 336276 sequences. (Running on oeis4.)