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A272954
Number of nX4 0..1 arrays with exactly n+4-2 having value 1 and no three 1s forming an isosceles right triangle.
1
4, 21, 24, 60, 210, 637, 1840, 5792, 18556, 54034, 160246, 499140, 1501706, 4627363, 13954490, 43064736, 131174878, 399170874, 1222825766, 3739040310, 11456400210, 35068696769, 107362206600, 329271410590, 1009129910706, 3096269613087
OFFSET
1,1
COMMENTS
Column 4 of A272958.
LINKS
EXAMPLE
Some solutions for n=5
..0..1..1..0. .1..0..0..1. .0..0..1..1. .0..1..1..1. .1..0..1..0
..1..0..0..1. .0..1..1..0. .0..0..0..0. .0..0..0..0. .0..0..0..1
..0..0..0..0. .0..0..0..0. .1..0..0..1. .0..0..1..0. .0..0..0..1
..1..0..0..1. .0..0..0..0. .1..0..1..0. .0..0..0..1. .0..0..1..0
..0..1..0..0. .1..0..1..1. .1..0..0..0. .0..1..0..1. .1..1..0..0
CROSSREFS
Cf. A272958.
Sequence in context: A138228 A303722 A305225 * A133784 A041821 A042429
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 11 2016
STATUS
approved