login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A260132 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010101 01010101 or 01010111. 1
58, 128, 342, 730, 1626, 3928, 8998, 20376, 47424, 109650, 251290, 579658, 1338500, 3080858, 7097716, 16367912, 37715574, 86898450, 200293226, 461601736, 1063705902, 2451421760, 5649587496, 13019565474, 30004282786, 69147284586 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = a(n-1) + a(n-2) + 5*a(n-3) + a(n-4) - 3*a(n-5) - 3*a(n-6) for n>7.

Empirical g.f.: 2*x*(29 + 35*x + 78*x^2 - 15*x^3 - 72*x^4 - 46*x^5 + 5*x^6) / (1 - x - x^2 - 5*x^3 - x^4 + 3*x^5 + 3*x^6). - Colin Barker, Dec 28 2018

EXAMPLE

Some solutions for n=4:

..1..0..1..0....0..0..1..1....1..0..1..0....0..1..0..1....1..0..0..0

..0..1..0..0....0..1..0..1....1..1..0..1....0..0..1..0....0..1..0..1

..1..0..1..0....1..0..1..0....1..0..1..0....0..1..0..1....1..0..1..0

..1..1..0..1....0..1..0..1....0..1..0..1....1..0..1..0....0..1..0..1

..1..0..1..0....1..0..1..0....0..0..1..0....1..1..0..1....1..0..0..0

..0..1..0..1....1..1..0..0....0..1..0..1....1..0..1..0....0..1..0..1

CROSSREFS

Column 2 of A260138.

Sequence in context: A044626 A039536 A348569 * A180571 A044309 A044690

Adjacent sequences:  A260129 A260130 A260131 * A260133 A260134 A260135

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 17 2015

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 January 26 13:09 EST 2022. Contains 350598 sequences. (Running on oeis4.)