A181031 Array read by antidiagonals: T(n,k) = number of n X k binary matrices with no initial bit string in any row or column divisible by 4.

1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 5, 7, 5, 1, 1, 8, 17, 17, 8, 1, 1, 13, 41, 63, 41, 13, 1, 1, 21, 99, 227, 227, 99, 21, 1, 1, 34, 239, 827, 1234, 827, 239, 34, 1, 1, 55, 577, 2999, 6743, 6743, 2999, 577, 55, 1, 1, 89, 1393, 10897, 36787, 55447, 36787, 10897, 1393, 89, 1, 1, 144

Offset

1,5

Comments

A089980 is essentially the same array (see the Comments by Steve Butler in A006506). - N. J. A. Sloane, Jan 27 2015

Links

R. H. Hardin, Table of n, a(n) for n=1..1057

Example

Table starts
.1..1....1......1.......1.........1...........1............1..............1
.1..2....3......5.......8........13..........21...........34.............55
.1..3....7.....17......41........99.........239..........577...........1393
.1..5...17.....63.....227.......827........2999........10897..........39561
.1..8...41....227....1234......6743.......36787.......200798........1095851
.1.13...99....827....6743.....55447......454385......3729091.......30584687
.1.21..239...2999...36787....454385.....5598861.....69050253......851302029
.1.34..577..10897..200798...3729091....69050253...1280128950....23720149995
.1.55.1393..39561.1095851..30584687...851302029..23720149995...660647962955
.1.89.3363.143677.5980913.250916131.10496827403.439621976195.18403310404291
Some solutions for 5X5
..1..1..1..1..1....1..1..1..1..1....1..1..1..1..1....1..1..1..1..1
..1..0..1..0..1....1..0..1..0..1....1..0..1..0..1....1..0..1..0..1
..1..1..0..1..0....1..1..0..1..0....1..1..0..1..0....1..1..0..1..0
..1..0..1..0..1....1..0..1..0..1....1..0..1..0..1....1..0..1..0..1
..1..1..0..1..0....1..1..0..1..1....1..1..1..1..0....1..1..1..1..1

Crossrefs

Cf. A089980.

Sequence in context: A113983 A199333 A089980 * A214987 A203946 A128545

Adjacent sequences: A181028 A181029 A181030 * A181032 A181033 A181034

Keyword

nonn,tabl

Author

R. H. Hardin, Sep 30 2010

Status

approved