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A067967 Number of binary arrangements without adjacent 1's on n X n hexagonal staggered torus shifted for odd n.

%I A067967 #14 Nov 18 2023 22:24:09
%S A067967 1,5,19,217,4076,164258,12285477,1834600977,527717587843,
%T A067967 296979228487760,324881629286870822,692625866382651263578,
%U A067967 2874716493700380888930840,23237986479606982160703729647,365788614113216462103977935612524,11213018647250714014261414954480048385
%N A067967 Number of binary arrangements without adjacent 1's on n X n hexagonal staggered torus shifted for odd n.
%D A067967 Steven R. Finch, Mathematical Constants, Cambridge, 2003, pp. 342-349.
%H A067967 Steven R. Finch, <a href="http://www.people.fas.harvard.edu/~sfinch/constant/square/square.html">Hard Square Entropy Constant</a> [Broken link]
%H A067967 Steven R. Finch, <a href="http://web.archive.org/web/20010605012506/http://www.mathsoft.com/asolve/constant/square/square.html">Hard Square Entropy Constant</a> [From the Wayback machine]
%e A067967 Neighbors for n=4:
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%e A067967 :-o--o--o--o-
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%e A067967 :-o--o--o--o-
%e A067967 : | /|\ | /|\
%e A067967 :\|/ | \|/ |
%e A067967 :-o--o--o--o-
%e A067967 : | /|\ | /|\
%e A067967 :\|/ | \|/ |
%e A067967 :-o--o--o--o-
%e A067967 : | /|\ | /|\
%e A067967 Neighbors for n=5:
%e A067967 :\|/ | \|/ | \|
%e A067967 :-o--o--o--o--o-
%e A067967 : | /|\ | /|\ |\
%e A067967 :\|/ | \|/ | \|
%e A067967 :-o--o--o--o--o-
%e A067967 : | /|\ | /|\ |\
%e A067967 :\|/ | \|/ | \|
%e A067967 :-o--o--o--o--o-
%e A067967 : | /|\ | /|\ |\
%e A067967 :\|/ | \|/ | \|
%e A067967 :-o--o--o--o--o-
%e A067967 : | /|\ | /|\ |\
%e A067967 :\|/ | \|/ | \|
%e A067967 :-o--o--o--o--o-
%e A067967 : | /|\ | /|\ |\
%Y A067967 For bent instead of shifted for odd n see A066865.
%K A067967 nonn
%O A067967 1,2
%A A067967 _R. H. Hardin_, Feb 02 2002
%E A067967 More terms from _Sean A. Irvine_, Nov 18 2023