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Numbers with divisors which are half odious (A000069) and half evil (A001969).
4

%I #15 Sep 23 2019 13:28:01

%S 3,5,6,10,12,17,20,23,24,29,33,34,39,40,43,46,48,53,57,58,63,65,66,68,

%T 69,71,78,80,83,86,87,89,92,95,96,101,105,106,111,113,114,115,116,117,

%U 119,123,125,126,130,132,136,138,139,141,142,145,149,156,160,163,166,171,172,174,177,178,183

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

%H Amiram Eldar, <a href="/A230851/b230851.txt">Table of n, a(n) for n = 1..10000</a>

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

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

%o (PARI) is(n)=!sumdiv(n,d,(-1)^hammingweight(d)) \\ _Charles R Greathouse IV_, Oct 31 2013

%Y Cf. A000069, A001969, A167171, A227872.

%K nonn

%O 1,1

%A _Juri-Stepan Gerasimov_, Oct 31 2013

%E Corrected by _Charles R Greathouse IV_, Oct 31 2013