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A135352
Period 5: repeat [1,2,2,1,3].
2
1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3, 1, 2, 2, 1, 3
OFFSET
1,2
COMMENTS
This sequence (if extended to be bi-infinite) is the quiddity sequence of the unique width-5 Coxeter frieze pattern A139434; equivalently, if one goes around the (uniquely) triangulated regular pentagon and sequentially looks at its vertices, counting the number of triangles incident with each vertex, then this sequence will be obtained. - Andrey Zabolotskiy, May 04 2023
LINKS
Karin Baur, Frieze Patterns of Integers, Math. Intelligencer 43, 47-54 (2021). See Example 2 and Figure 4.
CROSSREFS
Sequence in context: A283196 A238882 A279287 * A320040 A072528 A368060
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, Feb 16 2008
EXTENSIONS
Edited by Joerg Arndt, Oct 11 2016
Initial term 1 removed by Joerg Arndt, May 04 2023
STATUS
approved