OFFSET
1,1
REFERENCES
Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Sections 2.7, 6.2 and 9.4.
CROSSREFS
KEYWORD
hard,nonn,changed
AUTHOR
Joseph Myers, Oct 10 2011
EXTENSIONS
a(16)-a(18) from Johann Peters, Dec 17 2024
STATUS
approved