Voozh

A231125

Number of (n+1) X (2+1) white-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.

2, 8, 40, 176, 808, 3584, 16368, 72640, 331648, 1471872, 6719936, 29823488, 136161152, 604291584, 2758934016, 12244319232, 55902265856, 248097701888, 1132706802688, 5027022614528, 22951211032576, 101858889359360

(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.: 2*x*(1 + 4*x - 2*x^2) / (1 - 22*x^2 + 36*x^4 - 16*x^6). - Colin Barker, Sep 26 2018

EXAMPLE

Some solutions for n=5:

..0..x..1....0..x..0....0..x..1....0..x..0....0..x..1....0..x..0....0..x..1

..x..2..x....x..1..x....x..2..x....x..1..x....x..2..x....x..1..x....x..2..x

..1..x..2....2..x..0....2..x..0....0..x..2....1..x..2....1..x..1....0..x..0

..x..1..x....x..1..x....x..1..x....x..0..x....x..1..x....x..2..x....x..2..x

..2..x..0....2..x..0....2..x..0....2..x..0....0..x..0....2..x..0....0..x..2

..x..2..x....x..0..x....x..0..x....x..2..x....x..2..x....x..0..x....x..0..x

CROSSREFS

Column 2 of A231131.

Sequence in context: A003445 A181326 A220964 * A221587 A186947 A071007

Adjacent sequences: A231122 A231123 A231124 * A231126 A231127 A231128

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2013

STATUS

approved

URL: https://oeis.org/A231125

⇱ A231125 - OEIS