Search: id:A006069 Results 1-1 of 1 results found. %I A006069 M1903 %S A006069 2,8,96,43008,58018928640 %N A006069 Number of directed Hamiltonian cycles (or Gray codes) on n-cube with a marked starting node. %C A006069 More precisely, this is the number of ways of making a list of the 2^n nodes of the n-cube, with a distinguished starting position and a direction, such that each node is adjacent to the previous one and the last node is adjacent to the first. %D A006069 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A006069 M. Gardner, Knotted Doughnuts and Other Mathematical Entertainments. Freeman, NY, 1986, p. 24. %H A006069 Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics. %F A006069 a(n)=A003042(n)*2^n. - Max Alekseyev, Jun 15 2006 %e A006069 a(1) = 2: we have 1,2 or 2,1. %e A006069 a(2) = 8: label the nodes 1, 2, ..., 4. Then the 8 possibilities are 1,2,3,4; 1,4,3,2; 2,3,4,1; 2,1,4,3; etc. %Y A006069 Cf. A003042, A006070, A091299. %Y A006069 Sequence in context: A001417 A156926 A001697 this_sequence A052457 A119654 A008926 %Y A006069 Adjacent sequences: A006066 A006067 A006068 this_sequence A006070 A006071 A006072 %K A006069 nonn,more %O A006069 1,1 %A A006069 N. J. A. Sloane (njas(AT)research.att.com). %E A006069 a(5) corrected by Jonathan Cross (jcross(AT)wcox.com), Oct 10 2001 %E A006069 Definition corrected by Max Alekseyev, Jun 15 2006 Search completed in 0.001 seconds