OFFSET
0,3
REFERENCES
F. Harary and E. Palmer, Graphical Enumeration, Academic Press, 1973.
LINKS
Math StackExchange, A 4 x 4 grid of squares.
Marko Riedel, Maple code, Power Group Enumeration
CROSSREFS
KEYWORD
nonn
AUTHOR
Marko Riedel, Nov 22 2015
STATUS
approved