Search: id:A006068 Results 1-1 of 1 results found. %I A006068 M2253 %S A006068 0,1,3,2,7,6,4,5,15,14,12,13,8,9,11,10,31,30,28,29,24,25,27,26,16,17, %T A006068 19,18,23,22,20,21,63,62,60,61,56,57,59,58,48,49,51,50,55,54,52,53,32, %U A006068 33,35,34,39,38,36,37,47,46,44,45,40,41,43,42,127,126,124,125,120,121 %N A006068 a(n) is Gray-coded into n. %C A006068 Equivalently, if binary expansion of n has m bits (say), compute derivative of n (A038554), getting sequence n' of length m-1; sort on n'. %C A006068 Inverse of sequence A003188 considered as a permutation of the nonnegative integers, i.e. A006068(A003188(n)) = n = A003188(A006068(n)). - Howard A. Landman (howard(AT)polyamory.org), Sep 25 2001 %D A006068 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A006068 M. Gardner, Mathematical Games, Sci. Amer. Vol. 227 (No. 2, Feb. 1972), p. 107. %D A006068 M. Gardner, Knotted Doughnuts and Other Mathematical Entertainments. Freeman, NY, 1986, p. 15. %H A006068 T. D. Noe, Table of n, a(n) for n=0..1023 %H A006068 Index entries for sequences that are permutations of the natural numbers %F A006068 a(n) =2*a(ceiling[(n+1)/2])+A010060(n-1). If 3*2^(k-1) < n <= 2^(k+1), a(n)=2^(k+1)-1-a(n-2^k); if 2^(k+1) < n <= 3*2^k, a(n)=a(n-2^k)+2^k. %F A006068 a(n) = n XOR [n/2] XOR [n/4] XOR [n/8] ... XOR [n/2^m] where m = [log(n)/ log(2)] (for n>0) and [x] is integer floor of x. - Paul D. Hanna (pauldhanna(AT)juno.com), Jun 04 2002 %F A006068 A066194(n) = a(n-1) + 1, n>=1 . - Philippe DELEHAM, Apr 29 2005 %F A006068 Inverse of sequence A003188 . - Philippe DELEHAM, Apr 29 2005 %e A006068 The first few values of n' are -,-,1,0,10,11,01,00,100,101,111,110,010, 011,001,000,... (for n=0..15) and to put these in lexicographic order we must take n in the order 0,1,3,2,7,6,4,5,15,14,12,13,8,9,11,10, ... %Y A006068 Cf. A038554, A005811, A003188, A014550, A003100. %Y A006068 Sequence in context: A099896 A160679 A153141 this_sequence A154436 A072764 A130328 %Y A006068 Adjacent sequences: A006065 A006066 A006067 this_sequence A006069 A006070 A006071 %K A006068 nonn,easy,nice %O A006068 0,3 %A A006068 N. J. A. Sloane (njas(AT)research.att.com). %E A006068 Formula and more terms from Henry Bottomley (se16(AT)btinternet.com), Jan 10 2001 Search completed in 0.001 seconds