A146155 Number of n X n binary arrays symmetric about main diagonal with all ones connected only either as two by three or three by two blocks.

1, 1, 1, 1, 3, 7, 14, 42, 163, 719, 3628, 22263, 164206, 1435593, 15071126, 189778079, 2837151684, 50511089269, 1077365551719, 27499985838212, 837318042012350, 30417349994865723, 1319974251781005014, 68432608866087524550

Offset

1,5

Links

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

Example

Maximal 8 X 8 example
.0.0.0.1.1.0.0.0
.0.0.0.1.1.0.0.0
.0.0.0.1.1.0.0.0
.1.1.1.0.0.0.1.1
.1.1.1.0.0.0.1.1
.0.0.0.0.0.0.1.1
.0.0.0.1.1.1.0.0
.0.0.0.1.1.1.0.0

Crossrefs

Sequence in context: A184264 A298913 A266019 * A106363 A128658 A234042

Adjacent sequences: A146152 A146153 A146154 * A146156 A146157 A146158

Keyword

nonn

Author

R. H. Hardin, Oct 27 2008

Status

approved