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Search: id:A066372
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| A066372 |
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Number of different shapes formed by bending a piece of wire of length n in the plane. |
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+0
1
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OFFSET
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1,3
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COMMENT
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Wire is marked into n equal segments by n-1 marks, is bent at right angles at each of these points, making each segment parallel to one of two rectangular axes. (Stays in plane, bends are of +-90 degs.) May cross itself but is not self-coincident over a finite length. Two configurations which differ only in a rotation or turning over are not counted as different.
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REFERENCES
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Deborah Freedman, dlf(AT)alumni.princeton.edu, personal communication.
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LINKS
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R. Knott, Watch Out for Fibonacci Forgeries - Right-Angled Links?
Index entries for sequences obtained by enumerating foldings
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EXAMPLE
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Let LRUD denote left, right, up, down. Then for n = 1..4 the solutions are R, RD, RDL, RDR, RDLU, RDLD, RDRD. For n=5 the 5 shapes are
__.__. __....__ |__.... .__.... __......
..|__| ..|__|.. ...|__| |..|__| ..|__...
...... ........ ....... ....... .....|__
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CROSSREFS
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See A001997 for another version.
Sequence in context: A065955 A104880 A102973 this_sequence A058519 A082095 A006982
Adjacent sequences: A066369 A066370 A066371 this_sequence A066373 A066374 A066375
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KEYWORD
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more,nonn,nice
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AUTHOR
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Richard D. Plotz (Dick(AT)Plotz.com), Dec 22 2001
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