A123666 Numbers with an even number of prime factors, at least half of which are 2.

1, 4, 6, 10, 14, 16, 22, 24, 26, 34, 36, 38, 40, 46, 56, 58, 60, 62, 64, 74, 82, 84, 86, 88, 94, 96, 100, 104, 106, 118, 122, 132, 134, 136, 140, 142, 144, 146, 152, 156, 158, 160, 166, 178, 184, 194, 196, 202, 204, 206, 214, 216, 218, 220, 224, 226, 228, 232, 240

Offset: 1

Author

Franklin T. Adams-Watters, Oct 04 2006

Keywords

• nonn

Comments

This is the lexicographically earliest maximal set of nonprime integers that has unique factorization. Products of any number of terms from A100484, with repetition allowed.

Links

• James C. McMahon, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A100484, A002808, A123667.

Programs

Mathematica

fn[b_]:=Total[Last/@FactorInteger[b]];Join[{1},Select[Range[240],EvenQ[#]&&EvenQ[fn[#]]&&First[FactorInteger[#]][[2]]>=fn[#]/2&]] (* James C. McMahon, Nov 23 2024 *)