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%I #11 Aug 05 2023 13:04:12
%S 4,224,168960,1705639936,229940737867776,413561647491497066496,
%T 9918120959299139713735065600
%N The number of stones-and-bones tilings of the (3n+1,3n+1)-benzel when one orientation of bone is forbidden.
%C See Problem 9 of the Propp article. It is conjectured that a(n) is 2-adically continuous as a function of n.
%H James Propp, <a href="https://arxiv.org/abs/2206.06472">Trimer covers in the triangular grid: twenty mostly open problems</a>, arXiv:2206.06472 [math.CO], 2022.
%Y Cf. A352207, A364482, A364483, A364416, A364417, A364418, A364438.
%K nonn,more
%O 1,1
%A _James Propp_, Jul 26 2023