A146432 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 101-111-101 pattern in any orientation.

1, 1, 1, 1, 1, 3, 7, 13, 27, 99, 409, 1589, 6601, 37581, 257850, 1891375, 15191004, 148990011, 1749816180, 23213477355, 345838116504, 6040299518273, 124363503908437, 2949204267636321, 79815904035468955, 2501797176290873519

Offset

1,6

Links

Table of n, a(n) for n=1..26.

Example

Maximal 8 X 8 example
.0.0.0.0.1.0.1.0
.0.0.0.0.1.1.1.0
.0.0.0.0.1.0.1.0
.0.0.0.0.0.0.0.0
.1.1.1.0.0.0.0.0
.0.1.0.0.0.0.0.0
.1.1.1.0.0.0.0.0
.0.0.0.0.0.0.0.0

Crossrefs

Sequence in context: A098479 A119445 A146904 * A258349 A089726 A093575

Adjacent sequences: A146429 A146430 A146431 * A146433 A146434 A146435

Keyword

nonn

Author

R. H. Hardin

Status

approved