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Search: id:A143580
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%I A143580
%S A143580 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,0,1,1,
%T A143580 0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,
%U A143580 0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,0
%N A143580 A143579 mod 2.
%C A143580 Two conjectures: If n is even, the ratio of 1's to 0's = 1:1.
%C A143580 There are no three adjacent terms of the same parity.
%C A143580 Conjecture (verified for the first 280000 entries): this is the characteristic 
               function of A001969 and therefore a duplicate of A010059. [From R. 
               J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 05 2008]
%F A143580 Parity of A143579 (Odious numbers interleaved with Evil numbers); A000069 
               = Odious numbers, A001969 = Evil numbers).
%e A143580 First few terms of A143579 = (1, 0, 2, 3, 4, 5, 7,...), mod 2 = (1, 0, 
               0, 1, 0, 1, 1,...).
%t A143580 od = Select[ Range[0, 129], OddQ@ DigitCount[ #, 2, 1] &]; ev = Select[ 
               Range[0, 129], EvenQ@ DigitCount[ #, 2, 1] &]; Mod[ Flatten@ Transpose[{od, 
               ev}], 2] [From Robert G. Wilson v (rgwv(AT)rgwv.com), Apr 14 2009]
%Y A143580 Cf. A010060, A000069, A001969.
%Y A143580 Sequence in context: A005171 A076404 A010059 this_sequence A011749 A104105 
               A143221
%Y A143580 Adjacent sequences: A143577 A143578 A143579 this_sequence A143581 A143582 
               A143583
%K A143580 nonn
%O A143580 0,1
%A A143580 Gary W. Adamson (qntmpkt(AT)yahoo.com), Aug 24 2008
%E A143580 More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Apr 14 2009

    
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Last modified December 6 22:55 EST 2009. Contains 170429 sequences.


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