A230851 - OEIS

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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

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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