A230851 Numbers with divisors which are half odious (A000069) and half evil (A001969).

3, 5, 6, 10, 12, 17, 20, 23, 24, 29, 33, 34, 39, 40, 43, 46, 48, 53, 57, 58, 63, 65, 66, 68, 69, 71, 78, 80, 83, 86, 87, 89, 92, 95, 96, 101, 105, 106, 111, 113, 114, 115, 116, 117, 119, 123, 125, 126, 130, 132, 136, 138, 139, 141, 142, 145, 149, 156, 160, 163, 166, 171, 172, 174, 177, 178, 183

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

Numbers n such that d(n) = 2*A227872(n) where A227872(n) is number of odious divisors of n.

Mathematica

aQ[n_] := DivisorSum[n, (-1)^DigitCount[#, 2][[1]] &] == 0; Select[Range[200], aQ] (* Amiram Eldar, Sep 23 2019 *)

Prog

(PARI) is(n)=!sumdiv(n, d, (-1)^hammingweight(d)) \\ Charles R Greathouse IV, Oct 31 2013

Crossrefs

Cf. A000069, A001969, A167171, A227872.

Sequence in context: A140449 A207063 A359584 * A334101 A265749 A115823

Adjacent sequences: A230848 A230849 A230850 * A230852 A230853 A230854

Keyword

nonn

Author

Juri-Stepan Gerasimov, Oct 31 2013

Extensions

Corrected by Charles R Greathouse IV, Oct 31 2013

Status

approved