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%I A319324 #22 Jun 06 2024 12:28:24
%S A319324 2,12,88,710,6054,53500,484784,4475010,41902626,396838992,3793117200,
%T A319324 36534684066
%N A319324 a(n) is the number of fixed polyglasses (polyiamonds which need only touch at corners) with n cells.
%C A319324 Polyglasses are to polyiamonds (A001420) as polyplets (A006770) are to polyominoes (A001168). The name derives from the 2-celled animal (diglass) which looks like an hourglass.
%H A319324 David Bevan, <a href="/A319324/a319324.png">The 88 fixed triglasses.</a>
%H A319324 Rebecca M. Bowen, Sadie Pruitt, and Douglas A. Torrance, <a href="https://arxiv.org/abs/2405.20793">Properties of regular Tangles</a>, arXiv:2405.20793 [math.CO], 2024. See p. 2.
%H A319324 Adam Gruber, <a href="https://devweb3000.cis.strath.ac.uk/~xpb16190/LatticeAnimals/LatticeAnimals.jar">Java program to count lattice animals</a>.
%e A319324 a(2) = 12: three rotations of a diamond, three rotations of an hourglass and six rotations of "two mountains".
%Y A319324 Cf. A001420 (fixed polyiamonds), A319325 (row convex polyglasses), A319326 (column convex polyglasses).
%K A319324 nonn,more,hard
%O A319324 1,1
%A A319324 _David Bevan_, Sep 18 2018
%E A319324 a(12) from _Aaron N. Siegel_, May 22 2022

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