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%I #23 Aug 07 2024 11:26:18
%S 2,2,3,3,7,4,8,5,9,6,10,7,11,8,12,9,13,10,14,11,15,12,16,13,17,14,18,
%T 15,19,16,20,17,21,18,22,19,23,20,24,21,25,22,26,23,27,24,28,25,29,26,
%U 30,27,31,28,32,29,33,30,34,31,35,32,36,33,37,34,38,35
%N Number of congruences of the 0-twisted Temperley-Lieb monoid of degree n.
%H Matthias Fresacher, <a href="/A373011/b373011.txt">Table of n, a(n) for n = 0..10000</a>
%H J. East and N. Ruškuc, <a href="https://doi.org/10.1016/j.aim.2021.108097">Classification of congruences of twisted partition monoids</a>, Advances in Mathematics, 395 (2022); <a href="https://arxiv.org/abs/2010.04392">arXiv version</a>, arXiv:2010.04392 [math.RA], 2020.
%H J. East, J. Mitchell, N. Ruškuc and M. Torpey, <a href="https://doi.org/10.1016/j.aim.2018.05.016">Congruence lattices of finite diagram monoids</a>, Advances in Mathematics, 333 (2018), 931-1003; <a href="https://arxiv.org/abs/1709.00142">arXiv version</a>, arXiv:1709.00142 [math.GR], 2018.
%H Matthias Fresacher, <a href="https://www.youtube.com/watch?v=YPiSVZY1z7k">(10min B&TL) Congruence Lattices of Finite Twisted Brauer & Temperley-Lieb Monoids-MatthiasFresacher</a>, youtube video (2024).
%H Matthias Fresacher, <a href="https://www.youtube.com/watch?v=X9hDw0vNxYA">(50min B&TL) Congruence Lattices of Finite Twisted Brauer & Temperley-Lieb Monoids-MatthiasFresacher</a>, youtube video (2024).
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,-1).
%F a(n) = (n + 3)/2 if n is odd.
%F a(n) = (n + 10)/2 if n is even and n >= 4.
%F a(n) = a(n-2) + 1 for n >= 5.
%t LinearRecurrence[{1, 1, -1}, {2, 2, 3, 3, 7, 4}, 100] (* _Paolo Xausa_, Aug 07 2024 *)
%o (PARI) a(n)=if(n%2, (n+3)/2, n>2, n/2+5, n/2+2) \\ _Charles R Greathouse IV_, Aug 07 2024
%Y Closely related to A368923.
%K easy,nonn
%O 0,1
%A _Matthias Fresacher_, May 23 2024