%I #31 Jan 26 2024 15:14:51
%S 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,
%T 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,
%U 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
%N Period 5: repeat [1,2,2,1,3].
%C 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
%H G. C. Greubel, <a href="/A135352/b135352.txt">Table of n, a(n) for n = 1..1000</a>
%H Karin Baur, <a href="https://doi.org/10.1007/s00283-021-10065-x">Frieze Patterns of Integers</a>, Math. Intelligencer 43, 47-54 (2021). See Example 2 and Figure 4.
%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,1).
%Y Cf. A076839, A139434.
%K nonn,easy
%O 1,2
%A _Roger L. Bagula_, Feb 16 2008
%E Edited by _Joerg Arndt_, Oct 11 2016
%E Initial term 1 removed by _Joerg Arndt_, May 04 2023