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A253463 Number of (n+1) X (2+1) 0..2 arrays with every 2 X 2 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally, vertically, diagonally and antidiagonally. 1
540, 800, 1400, 3072, 8536, 15888, 44464, 94416, 273808, 562320, 1622320, 3376272, 9768496, 20246928, 58535344, 121496976, 351356848, 728945040, 2107845040, 4373737872, 12647655856, 26242285968, 75884757424, 157453992336 (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) = 5*a(n-2) + 8*a(n-4) - 12*a(n-6) for n>7.

Empirical g.f.: 4*x*(135 + 200*x - 325*x^2 - 232*x^3 - 696*x^4 - 1468*x^5 - 734*x^6) / ((1 - x)*(1 + x)*(1 + 2*x^2)*(1 - 6*x^2)). - Colin Barker, Dec 14 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Column 2 of A253468.

Sequence in context: A289221 A345390 A261290 * A255105 A298685 A185463

Adjacent sequences:  A253460 A253461 A253462 * A253464 A253465 A253466

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 01 2015

STATUS

approved

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Last modified May 24 05:06 EDT 2022. Contains 354005 sequences. (Running on oeis4.)