A146044 - OEIS

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A146044

Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 2X4 tee 1,1 1,2 1,3 2,3 1,4 in any orientation.

1, 1, 1, 1, 1, 7, 15, 37, 79, 277, 1211, 6171, 28503, 152765, 945077, 7764777, 66517839, 667569119, 7061433273, 91063498499, 1300158727279, 22513920414055

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,6

LINKS

Table of n, a(n) for n=1..22.

EXAMPLE

Maximal 8 X 8 example

.0.0.0.0.0.1.0.0

.0.0.0.0.1.1.0.0

.1.1.1.1.0.1.0.0

.0.1.0.0.0.1.0.0

.0.0.1.0.0.0.1.0

.0.0.1.0.1.1.1.1

.0.0.1.1.0.0.0.0

.0.0.1.0.0.0.0.0

CROSSREFS

Sequence in context: A159792 A247606 A146837 * A048694 A041094 A042287

Adjacent sequences: A146041 A146042 A146043 * A146045 A146046 A146047

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 26 2008

STATUS

approved