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A084345 Numbers with a nonprime number of 1's in their binary expansion (complement of A052294). 6

%I #27 Aug 28 2013 04:09:21

%S 0,1,2,4,8,15,16,23,27,29,30,32,39,43,45,46,51,53,54,57,58,60,63,64,

%T 71,75,77,78,83,85,86,89,90,92,95,99,101,102,105,106,108,111,113,114,

%U 116,119,120,123,125,126,128,135,139,141,142,147,149,150,153,154,156,159,163

%N Numbers with a nonprime number of 1's in their binary expansion (complement of A052294).

%H Reinhard Zumkeller, <a href="/A084345/b084345.txt">Table of n, a(n) for n = 1..10000</a>

%e 15 is in the sequence because 15_10=1111_2 and 1+1+1+1=4 is composite.

%t Select[Range[200],!PrimeQ[DigitCount[#,2,1]]&] (* _Harvey P. Dale_, Jan 21 2013 *)

%o (PARI) for(n=0,200,b=binary(n); if(!isprime(sum(m=1,matsize(b)[2],b[m])),print1(n,",")))

%o (Haskell)

%o a084345 n = a084345_list !! (n-1)

%o a084345_list = filter ((== 0) . a010051' . a000120) [0..]

%o -- _Reinhard Zumkeller_, Aug 28 2013, Nov 16 2012

%Y Cf. A052294.

%Y Cf. A010051, A000120.

%K easy,nonn,base

%O 1,3

%A _Zak Seidov_ Jun 22 2003

%E More terms from _Rick L. Shepherd_, Jun 23 2003

%E Term 0 added by _Michel Marcus_, Aug 26 2013

%E b-file adjusted by _Reinhard Zumkeller_, Aug 28 2013

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Last modified August 25 03:01 EDT 2024. Contains 375420 sequences. (Running on oeis4.)