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A272966 Number of n X n 0..1 arrays with exactly n+n-2 having value 1 and no three 1's forming an isosceles triangle. 0
1, 6, 12, 8, 4, 8, 4, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Diagonal of A272973.
LINKS
Table of n, a(n) for n=1..8.
EXAMPLE
Some solutions for n=3
..1..1..0. .1..0..1. .0..0..1. .0..1..1. .0..1..1. .1..0..0. .1..0..0
..0..0..0. .1..0..1. .1..0..1. .0..0..0. .0..0..0. .1..0..0. .1..0..1
..1..1..0. .0..0..0. .1..0..0. .0..1..1. .1..1..0. .0..1..1. .0..0..1
CROSSREFS
Cf. A272973.
Sequence in context: A175365 A029769 A074590 * A105730 A213384 A005875
Adjacent sequences: A272963 A272964 A272965 * A272967 A272968 A272969
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 11 2016
STATUS
approved

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Last modified May 14 14:46 EDT 2024. Contains 372533 sequences. (Running on oeis4.)