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

 

Logo

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 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A218759 Unmatched value maps: number of n X 2 binary arrays indicating the locations of corresponding elements not equal to any horizontal or vertical neighbor in a random 0..1 n X 2 array. 2
2, 6, 18, 47, 134, 373, 1035, 2889, 8050, 22420, 62477, 174072, 484983, 1351277, 3764915, 10489750, 29226504, 81430659, 226881448, 632135485, 1761251171, 4907184849, 13672362150, 38093833868, 106136756981, 295717444696 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A218765.

LINKS

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

FORMULA

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

Empirical g.f.: x*(2 + 2*x + 4*x^2 - x^3 + 4*x^4 - 2*x^6) / (1 - 2*x - x^2 - 3*x^3 - 2*x^5 - 2*x^6 + 2*x^7). - Colin Barker, Mar 10 2018

EXAMPLE

Some solutions for n=3:

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

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

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

CROSSREFS

Cf. A218765.

Sequence in context: A002529 A217526 A018027 * A295499 A059413 A256828

Adjacent sequences: A218756 A218757 A218758 * A218760 A218761 A218762

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 05 2012

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 9 03:54 EST 2022. Contains 358698 sequences. (Running on oeis4.)