A272961 Number of nX4 0..1 arrays with exactly n+4-1 having value 1 and no three 1s forming an isosceles right triangle.

1, 0, 1, 0, 8, 8, 71, 212, 731, 1840, 5953, 18632, 54705, 171348, 511899, 1608540, 4861373, 14726040, 45536993, 138776184, 426552305, 1305642816, 3998654049, 12283464960, 37639150053, 115651510068, 355188064346, 1090663423924

Offset

1,5

Comments

Column 4 of A272965.

Links

R. H. Hardin, Table of n, a(n) for n = 1..113

Example

Some solutions for n=6
..1..1..0..1. .1..1..1..0. .0..1..1..1. .1..0..1..1. .1..0..1..1
..0..0..0..1. .0..0..0..0. .0..0..0..0. .1..0..0..0. .1..0..0..0
..0..0..1..0. .0..1..0..0. .0..0..1..0. .0..1..0..0. .0..1..0..0
..0..0..0..0. .0..0..1..0. .0..1..0..0. .0..0..0..0. .0..0..1..0
..0..0..0..0. .0..0..0..1. .1..0..0..0. .0..0..0..0. .0..0..0..0
..1..1..1..1. .1..1..0..1. .1..0..1..1. .1..1..1..1. .0..1..1..1

Crossrefs

Cf. A272965.

Sequence in context: A183395 A019216 A020552 * A117861 A186984 A298962

Adjacent sequences: A272958 A272959 A272960 * A272962 A272963 A272964

Keyword

nonn

Author

R. H. Hardin, May 11 2016

Status

approved