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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. 1
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

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Last modified November 13 04:20 EST 2019. Contains 329085 sequences. (Running on oeis4.)