A146869 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1101-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 9, 29, 49, 117, 309, 1103, 4069, 20291, 72247, 389841, 1904157, 13920727, 88083783, 777496329, 5560593885, 59069816813

Offset

1,7

Links

Table of n, a(n) for n=1..22.

Example

Maximal 8 X 8 example
.0.0.0.0.0.1.1.0
.1.0.1.1.0.1.0.0
.1.1.1.1.0.1.1.0
.0.0.0.0.0.1.1.0
.0.1.1.0.0.0.0.0
.0.1.1.0.1.1.1.1
.0.0.1.0.1.1.0.1
.0.1.1.0.0.0.0.0

Crossrefs

Sequence in context: A350963 A098949 A031296 * A129397 A136392 A272732

Adjacent sequences: A146866 A146867 A146868 * A146870 A146871 A146872

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved