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

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A231134 Number of (n+1) X (2+1) black-square subarrays of 0..2 arrays with no element equal to a strict majority of its diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order. 1
 2, 9, 40, 182, 808, 3688, 16368, 74728, 331648, 1514160, 6719936, 30680320, 136161152, 621652928, 2758934016, 12596099456, 55902265856, 255225567744, 1132706802688, 5171449356800, 22951211032576, 104785303002112 (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) = 22*a(n-2) - 36*a(n-4) + 16*a(n-6). Empirical g.f.: x*(2 + 9*x - 4*x^2 - 16*x^3 + 8*x^5) / (1 - 22*x^2 + 36*x^4 - 16*x^6). - Colin Barker, Sep 26 2018 EXAMPLE Some solutions for n=5: ..x..0..x....x..0..x....x..0..x....x..0..x....x..0..x....x..0..x....x..0..x ..1..x..2....1..x..0....1..x..2....1..x..1....0..x..1....0..x..1....1..x..2 ..x..1..x....x..2..x....x..1..x....x..2..x....x..1..x....x..2..x....x..0..x ..0..x..0....0..x..0....0..x..1....1..x..1....2..x..0....2..x..0....1..x..2 ..x..1..x....x..2..x....x..0..x....x..2..x....x..2..x....x..1..x....x..0..x ..2..x..0....1..x..0....2..x..2....0..x..0....0..x..0....2..x..0....2..x..2 CROSSREFS Column 2 of A231137. Sequence in context: A020728 A107979 A021001 * A038112 A268039 A235596 Adjacent sequences:  A231131 A231132 A231133 * A231135 A231136 A231137 KEYWORD nonn AUTHOR R. H. Hardin, Nov 04 2013 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.

Last modified January 19 17:59 EST 2020. Contains 331051 sequences. (Running on oeis4.)