%I A005351 M4059
%S A005351 0,1,6,7,4,5,26,27,24,25,30,31,28,29,18,19,16,17,22,23,20,21,106,107,
%T A005351 104,105,110,111,108,109,98,99,96,97,102,103,100,101,122,123,120,121,
%U A005351 126,127,124,125,114,115,112,113,118,119,116,117,74,75,72,73,78,79,76
%N A005351 Numbers n such that base -2 representation for n converted from binary 
               to decimal.
%D A005351 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A005351 M. Gardner, Knotted Doughnuts and Other Mathematical Entertainments. 
               Freeman, NY, 1986, p. 101.
%H A005351 Joerg Arndt, <a href="http://www.jjj.de/fxt/#fxtbook">Fxtbook</a>
%H A005351 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Negabinary.html">Link to a section of The World of Mathematics.</
               a>
%F A005351 a(4n+2) = 4a(n+1)+2, a(4n+3) = 4a(n+1)+3, a(4n+4) = 4a(n+1), a(4n+5) 
               = 4a(n+1)+1, n>-2, a(1)=1. - R. Stephan, Apr 06 2004
%e A005351 2 = 4+(-2)+0 = 110 => 6, 3 = 4+(-2)+1 = 111 => 7, ..., 6 = (16)+(-8)+0+(-2)+0 
               = 11010 => 26.
%t A005351 f[n_] := Module[{t = 2(4^Floor[ Log[4, Abs[n] + 1] + 2] - 1)/3}, BitXor[n 
               + t, t]]; Table[ f[n]], {n, 0, 60}] (from Robert G. Wilson v Jan 
               24 2005)
%Y A005351 Cf. A039724. Complement of A005352.
%Y A005351 Sequence in context: A092678 A019932 A004447 this_sequence A098882 A019616 
               A073177
%Y A005351 Adjacent sequences: A005348 A005349 A005350 this_sequence A005352 A005353 
               A005354
%K A005351 nonn,base,easy,nice
%O A005351 1,3
%A A005351 N. J. A. Sloane (njas(AT)research.att.com).
%E A005351 More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 24 2005