A269861 Numbers n such that n and A048673(n) are of opposite parity.

4, 5, 7, 10, 12, 14, 15, 16, 17, 19, 21, 29, 30, 34, 36, 38, 40, 41, 42, 43, 44, 45, 48, 51, 52, 53, 55, 56, 57, 58, 61, 63, 64, 65, 67, 73, 77, 79, 82, 86, 87, 90, 91, 92, 100, 101, 102, 103, 106, 108, 110, 113, 114, 115, 120, 122, 123, 124, 125, 126, 127, 129, 130, 132, 134, 135, 136, 137, 140, 144, 146, 148, 149

Offset: 1

Author

Antti Karttunen, Mar 16 2016

Keywords

• nonn

Comments

Union of even terms of A246261 and odd terms of A246263.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000

Crossrefs

Complement: A269860.

Left inverse: A269862.

Cf. A000035, A048673, A246261, A246263.

Cf. also A270431.

Programs

Mathematica

f[n_] := (Times @@ Power[If[# == 1, 1, NextPrime@ #] & /@ First@ #, Last@ #] + 1)/2 &@ Transpose@ FactorInteger@ n; Select[Range@ 150, Xor[EvenQ@ f@ #, EvenQ@ #] &] (* Michael De Vlieger, Mar 17 2016 *)

Formula

Other identities. For all n >= 1:

A269862(a(n)) = n.