OFFSET
1,1
REFERENCES
Branko Gruenbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Sections 2.7, 6.2 and 9.4.
CROSSREFS
KEYWORD
hard,more,nonn
AUTHOR
Joseph Myers, Oct 15 2011
EXTENSIONS
a(18)-a(22) from Aaron N. Siegel, May 16 2022
STATUS
approved