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%I #22 Feb 25 2023 04:27:54
%S 0,0,0,1,0,0,2,1,0,0,0,5,4,4,2,1,0,0,0,1,0,0,10,9,8,8,8,5,4,4,2,1,0,0,
%T 0,1,0,0,2,1,0,0,0,21,20,20,18,17,16,16,16,17,16,16,10,9,8,8,8,5,4,4,
%U 2,1,0,0,0,1,0,0,2,1,0,0,0,5,4,4,2,1,0,0,0,1,0,0,42,41
%N Negated negative parts of the nonadjacent forms.
%C This sequence together with A184615 (positive parts) gives the (signed binary) nonadjacent form (NAF) of n, see fxtbook link and example in A184615.
%C No two adjacent bits in the binary representations of a(n) are 1.
%C No two adjacent bits in the binary representations of a(n)+A184615(n) are 1.
%H Rémy Sigrist, <a href="/A184616/b184616.txt">Table of n, a(n) for n = 0..8192</a>
%H Pages 61-62 of <a href="http://www.jjj.de/fxt/#fxtbook">Matters Computational (The Fxtbook)</a>.
%F A184615(n) - a(n) = n
%F a(n) + A184615(n) = A184617(n)
%e (see A184615)
%t bin2naf[x_] := Module[{xh, x3, c, np, nm},
%t xh = BitShiftRight[x, 1];
%t x3 = x + xh;
%t c = BitXor[xh, x3];
%t np = BitAnd[x3, c];
%t nm = BitAnd[xh, c];
%t Return[{np, nm}]];
%t a[n_] := bin2naf[n][[2]];
%t Table[a[n], {n, 0, 100}] (* _Jean-François Alcover_, May 30 2019, from PARI code in A184615 *)
%o (PARI) (see A184615)
%Y Cf. A184615 (positive parts), A184617 (sums of both parts =A184615+A184616).
%K nonn
%O 0,7
%A _Joerg Arndt_, Jan 18 2011
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