A147447 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 11000-01100-00110-00011 pattern in any orientation.

1, 1, 1, 1, 1, 3, 7, 13, 39, 123, 461, 2371, 13249, 80863, 611487, 5648891, 61162833, 795442861, 12190308735, 215424452659

Offset

1,6

Links

Table of n, a(n) for n=1..20.

Example

Maximal 8 X 8 example
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0
.0.0.0.0.1.0.0.0
.0.0.0.0.1.1.0.0
.0.0.1.1.0.1.1.0
.0.0.0.1.1.0.1.1
.0.0.0.0.1.1.0.1
.0.0.0.0.0.1.1.0

Crossrefs

Sequence in context: A145956 A155225 A051842 * A062605 A191974 A174241

Adjacent sequences: A147444 A147445 A147446 * A147448 A147449 A147450

Keyword

nonn

Author

R. H. Hardin

Status

approved