login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A145971 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a one by five or five by one block. 0
1, 1, 1, 1, 9, 9, 54, 93, 747, 1903, 18738, 80363, 1083847, 6706491, 120203159, 1028058854 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

Table of n, a(n) for n=1..16.

EXAMPLE

Maximal 8 X 8 example

.1.1.1.1.1.0.0.1

.0.0.0.0.0.0.0.1

.0.1.1.1.1.1.0.1

.1.0.0.0.0.0.0.1

.1.0.0.0.0.0.0.1

.1.0.1.1.1.1.1.0

.1.0.0.0.0.0.0.0

.1.0.0.1.1.1.1.1

CROSSREFS

Sequence in context: A141635 A014718 A339324 * A241868 A243125 A270008

Adjacent sequences:  A145968 A145969 A145970 * A145972 A145973 A145974

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 25 2008

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 7 19:49 EST 2021. Contains 341931 sequences. (Running on oeis4.)