A147508 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 11110-01111 pattern in any orientation.

1, 1, 1, 1, 1, 3, 9, 23, 81, 267, 1053, 6173, 40853, 301993, 2684783, 27089119, 322029889, 4723820567, 81998776493, 1660922956591, 39864394187483, 1124746291185333

Offset

1,6

Links

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

Example

Maximal 8 X 8 example
.0.1.1.1.1.0.0.0
.1.0.1.1.1.1.0.0
.1.1.0.0.0.0.1.0
.1.1.0.0.0.0.1.1
.1.1.0.0.0.0.1.1
.0.1.0.0.0.0.1.1
.0.0.1.1.1.1.0.1
.0.0.0.1.1.1.1.0

Crossrefs

Sequence in context: A018334 A146392 A116659 * A146472 A145955 A129834

Adjacent sequences: A147505 A147506 A147507 * A147509 A147510 A147511

Keyword

nonn

Author

R. H. Hardin

Status

approved