A259509 - OEIS

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

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A259509

Number of (n+1) X (2+1) 0..1 arrays with each 2 X 2 subblock having clockwise pattern 0000 0001 0101 0111.

31, 129, 533, 2219, 9227, 38409, 159845, 665339, 2769251, 11526489, 47976173, 199690619, 831166667, 3459548649, 14399597045, 59935131419, 249466635731, 1038349453209, 4321898626973, 17988942330779, 74874972302267

(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) = 2*a(n-1) + 11*a(n-2) - 4*a(n-3) - 18*a(n-4).

Empirical g.f.: x*(31 + 67*x - 66*x^2 - 142*x^3) / ((1 - 2*x^2)*(1 - 2*x - 9*x^2)). - Colin Barker, Dec 25 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Column 2 of A259515.

Sequence in context: A065403 A278054 A035502 * A183838 A043355 A023728

Adjacent sequences: A259506 A259507 A259508 * A259510 A259511 A259512

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 29 2015

STATUS

approved