A146447 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1100-0110-0011 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 9, 9, 33, 33, 185, 185, 1861, 1861, 35285, 35285, 845657, 845657, 28275879, 28275879, 1543673839, 1543673839, 135800422841, 135800422841

Offset

1,9

Links

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

Example

Maximal 9 X 9 example
.0.0.0.0.0.0.0.0.0
.1.1.0.0.0.0.0.1.1
.0.1.1.0.0.0.1.1.0
.0.0.1.1.0.1.1.0.0
.0.0.0.0.0.0.0.0.0
.0.0.1.1.0.1.1.0.0
.0.1.1.0.0.0.1.1.0
.1.1.0.0.0.0.0.1.1
.0.0.0.0.0.0.0.0.0

Crossrefs

Sequence in context: A147277 A146138 A147446 * A145954 A003874 A339735

Adjacent sequences: A146444 A146445 A146446 * A146448 A146449 A146450

Keyword

nonn

Author

R. H. Hardin

Status

approved