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Search: id:A067960
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| A067960 |
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Number of binary arrangements without adjacent 1's on n X n torus connected ne-sw nw-se. |
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+0
9
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| 1, 9, 34, 961, 25531, 2722500, 464483559, 224546142769, 215560806324388, 509113406167679889, 2590618817013278596997
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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Neighbors for n=4 (dots represent spaces):
.\ /\ /\ /\ /
. o..o..o..o
./ \/ \/ \/ \
.\ /\ /\ /\ /
. o..o..o..o
./ \/ \/ \/ \
.\ /\ /\ /\ /
. o..o..o..o
./ \/ \/ \/ \
.\ /\ /\ /\ /
. o..o..o..o
./ \/ \/ \/ \
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CROSSREFS
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Cf. circle A000204, line A000045, arrays: ne-sw nw-se A067965, e-w ne-sw nw-se A067963, n-s nw-se A067964, e-w n-s nw-se A066864, e-w ne-sw n-s nw-se A063443, n-s A067966, e-w n-s A006506, nw-se A067962, toruses: bare A002416, ne-sw n-s nw-se A067959, e-w ne-sw n-s nw-se A067958, n-s A067961, e-w n-s A027683, e-w ne-sw n-s A066866.
Sequence in context: A050478 A154393 A119389 this_sequence A119757 A003865 A085366
Adjacent sequences: A067957 A067958 A067959 this_sequence A067961 A067962 A067963
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KEYWORD
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nonn
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AUTHOR
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Ron Hardin (rhhardin(AT)att.net), Feb 02 2002
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