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A251277 Number of (n+1) X (2+1) 0..3 arrays with no 2 X 2 subblock having its maximum diagonal element less than its minimum antidiagonal element. 1
3264, 164800, 8320896, 420152704, 21215177472, 1071238805248, 54091113672192, 2731275752121856, 137912990258285568, 6963776128082148352, 351628790523862185984, 17755138024422940530688, 896527630165476145606656 (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) = 54*a(n-1) - 182*a(n-2) + 228*a(n-3) + 1152*a(n-4).

Empirical g.f.: 64*x*(51 - 179*x + 246*x^2 + 1152*x^3) / (1 - 54*x + 182*x^2 - 228*x^3 - 1152*x^4). - Colin Barker, Nov 27 2018

EXAMPLE

Some solutions for n=2:

..0..0..2....3..0..0....1..3..2....1..2..0....1..3..0....1..1..3....1..3..0

..1..2..3....3..1..1....0..2..2....2..3..2....0..0..1....0..1..1....0..0..2

..0..0..3....3..0..3....0..1..3....3..3..2....2..1..2....2..1..0....2..3..3

CROSSREFS

Column 2 of A251283.

Sequence in context: A254485 A253857 A337792 * A328148 A286008 A220594

Adjacent sequences:  A251274 A251275 A251276 * A251278 A251279 A251280

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 01 2014

STATUS

approved

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Last modified April 14 12:11 EDT 2021. Contains 342949 sequences. (Running on oeis4.)