A146244 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 110-111-010 pattern in any orientation.

1, 1, 1, 1, 3, 5, 15, 27, 71, 187, 699, 2485, 10357, 44365, 244417, 1388829, 9098951, 61499491, 509779147, 4539566193, 48133963115, 521951245563, 6723339029473, 91767923636107, 1516162394272495, 26177605341894705, 536020923137750911

Offset

1,5

Links

Table of n, a(n) for n=1..27.

Example

Maximal 8 X 8 example
.0.0.0.0.0.0.1.0
.0.0.1.0.0.1.1.1
.0.1.1.1.0.1.1.0
.0.0.1.1.0.0.0.0
.0.0.0.0.1.1.0.0
.0.1.1.0.1.1.1.0
.1.1.1.0.0.1.0.0
.0.1.0.0.0.0.0.0

Crossrefs

Sequence in context: A289881 A290230 A274638 * A146457 A051044 A353765

Adjacent sequences: A146241 A146242 A146243 * A146245 A146246 A146247

Keyword

nonn

Author

R. H. Hardin

Status

approved