A146472 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1110-0111 pattern in any orientation.

1, 1, 1, 1, 3, 9, 23, 85, 375, 2149, 15299, 129877, 1353943, 17475557, 279267939, 5511590965, 133957241929, 4003924495735, 147542199515841, 6704016396279819, 375798793326385295, 25965634034447375655

Offset

1,5

Links

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

Example

Maximal 8 X 8 example
.0.1.1.1.0.0.0.0
.1.0.1.1.1.0.0.0
.1.1.0.0.0.0.0.0
.1.1.0.0.0.0.1.0
.0.1.0.0.0.0.1.1
.0.0.0.0.0.0.1.1
.0.0.0.1.1.1.0.1
.0.0.0.0.1.1.1.0

Crossrefs

Sequence in context: A146392 A116659 A147508 * A145955 A129834 A376407

Adjacent sequences: A146469 A146470 A146471 * A146473 A146474 A146475

Keyword

nonn

Author

R. H. Hardin

Status

approved