A036350 Composite numbers such that the sum of the prime factors is odd (counted with multiplicity).

6, 10, 12, 14, 20, 22, 24, 26, 27, 28, 34, 38, 40, 44, 45, 46, 48, 52, 54, 56, 58, 62, 63, 68, 74, 75, 76, 80, 82, 86, 88, 90, 92, 94, 96, 99, 104, 105, 106, 108, 112, 116, 117, 118, 122, 124, 125, 126, 134, 136, 142, 146, 147, 148, 150, 152, 153, 158, 160, 164

Offset

1,1

Links

Table of n, a(n) for n=1..60.

Example

44 = 2 * 2 * 11 -> sum = 15 -> 15 is odd.

Mathematica

okQ[n_]:=!PrimeQ[n]&&OddQ[Total[Flatten[Table[First[#], {Last[#]}]&/@ FactorInteger[n]]]]; Select[Range[2, 200], okQ] (* Harvey P. Dale, Dec 18 2011 *)

Crossrefs

Cf. A001414, A046363, A036349.

Subsequence of A335657.

Sequence in context: A175352 A175397 A129493 * A295076 A088829 A036348

Adjacent sequences: A036347 A036348 A036349 * A036351 A036352 A036353

Keyword

nonn,base

Author

Patrick De Geest, Dec 15 1998

Status

approved