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A211179
Number of free polypentagrams with n cells.
2
1, 1, 5, 31, 238, 2020, 17754, 160820, 1479536, 13792972, 129839465
OFFSET
1,3
COMMENTS
A polypentagram is a plane figure made of five-pointed stars joined edge to edge. Free means that mirror images are counted as the same polypentagram.
EXAMPLE
Five different figures can be formed by joining 3 pentagrams, so a(3) = 5.
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
George Sicherman, Feb 01 2013
EXTENSIONS
a(6)-a(11) from Aaron N. Siegel, May 23 2022
STATUS
approved