OFFSET
1,1
COMMENTS
a(3) is also the number of Eulerian cycles in the 3 X 3 rook graph.
a(4) is also the number of Eulerian cycles in the 4-hypercube (tesseract) graph Q_4.
LINKS
Eric Weisstein's World of Mathematics, Eulerian Cycle
Eric Weisstein's World of Mathematics, Torus Grid Graph
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Eric W. Weisstein, Dec 29 2017
EXTENSIONS
a(4)-a(7) from Andrew Howroyd, Jan 12 2018
a(1)-a(2) from Andrew Howroyd, Jan 12 2018
STATUS
approved