A147038 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 0100-0100-1111-0100 pattern in any orientation.

1, 1, 1, 3, 5, 9, 21, 69, 305, 1333, 6087, 37147, 280959, 2501123, 26363255, 322801403, 4679667007, 81403804671, 1686900283495, 41922642406637, 1239283752468159, 43217375654523227, 1785265760870915049, 87797244145177135687

Offset

1,4

Links

Table of n, a(n) for n=1..24.

Example

Maximal 8 X 8 example
.0.0.1.0.0.0.1.0
.0.0.1.0.1.1.1.1
.1.1.1.1.0.0.1.0
.0.0.1.0.0.0.1.0
.0.1.0.0.0.1.0.0
.0.1.0.0.1.1.1.1
.1.1.1.1.0.1.0.0
.0.1.0.0.0.1.0.0

Crossrefs

Sequence in context: A129787 A328525 A125517 * A146275 A089636 A241398

Adjacent sequences: A147035 A147036 A147037 * A147039 A147040 A147041

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved