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A211179 Number of free polypentagrams with n cells. 0
1, 1, 5, 31, 238 (list; graph; refs; listen; history; text; internal format)
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.

LINKS

Table of n, a(n) for n=1..5.

George Sicherman, Catalogue of Polypentagrams

EXAMPLE

Five different figures can be formed by joining 3 pentagrams, so a(3) = 5.

CROSSREFS

Cf. A103465, A000105, A000507.

Sequence in context: A062147 A213048 A069321 * A177797 A293717 A186859

Adjacent sequences:  A211176 A211177 A211178 * A211180 A211181 A211182

KEYWORD

nonn,hard,more

AUTHOR

George Sicherman, Feb 01 2013

STATUS

approved

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Last modified September 22 22:24 EDT 2020. Contains 337291 sequences. (Running on oeis4.)