A259518 - OEIS

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A259518

Number of (n+1) X (2+1) 0..1 arrays with each 2 X 2 subblock having clockwise pattern 0000 0001 0011 0101 or 1111.

38, 208, 1122, 6100, 33162, 180370, 981092, 5336678, 29029222, 157906912, 858948710, 4672329330, 25415560796, 138250260726, 752024907134, 4090708107616, 22251780062734, 121040588343338, 658411326480860

(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) = 7*a(n-1) - 7*a(n-2) - 10*a(n-3) + 10*a(n-4) + 2*a(n-5).

Empirical g.f.: 2*x*(19 - 29*x - 34*x^2 + 41*x^3 + 8*x^4) / (1 - 7*x + 7*x^2 + 10*x^3 - 10*x^4 - 2*x^5). - Colin Barker, Dec 25 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Column 2 of A259524.

Sequence in context: A124238 A020870 A211502 * A209250 A165068 A160281

Adjacent sequences: A259515 A259516 A259517 * A259519 A259520 A259521

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 29 2015

STATUS

approved