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 A229521 T(n,k) = number of n X k 0..2 arrays of the median of the corresponding element, the element to the east and the element to the south in a larger (n+1) X (k+1) 0..2 array without adjacent equal elements in the latter. 9

%I

%S 3,7,7,17,33,17,39,129,129,39,91,481,775,481,91,211,1751,4193,4193,

%T 1751,211,491,6433,23059,34151,23059,6433,491,1141,23507,124431,

%U 275243,275243,124431,23507,1141,2653,86295,680991,2223913,3336437,2223913,680991

%N T(n,k) = number of n X k 0..2 arrays of the median of the corresponding element, the element to the east and the element to the south in a larger (n+1) X (k+1) 0..2 array without adjacent equal elements in the latter.

%C Table starts

%C ....3......7.......17.........39..........91...........211.............491

%C ....7.....33......129........481........1751..........6433...........23507

%C ...17....129......775.......4193.......23059........124431..........680991

%C ...39....481.....4193......34151......275243.......2223913........17910863

%C ...91...1751....23059.....275243.....3336437......39543877.......476435051

%C ..211...6433...124431....2223913....39543877.....701321971.....12425155219

%C ..491..23507...680991...17910863...476435051...12425155219....329002027139

%C .1141..86295..3698901..144971845..5674074209..220821219009...8615734849077

%C .2653.316099.20206283.1169783337.68219097971.3914741097513.227806404072631

%H R. H. Hardin, <a href="/A229521/b229521.txt">Table of n, a(n) for n = 1..179</a>

%F Empirical for column k:

%F k=1: a(n) = 2*a(n-1) + a(n-2) - a(n-3) + a(n-4).

%F k=2: [order 20].

%F k=3: [order 44] for n > 45.

%F k=4: [order 75] for n > 77.

%e Some solutions for n=3, k=4:

%e 2 0 1 1 2 0 1 1 1 0 1 1 2 0 2 1 1 0 1 1

%e 1 1 0 1 0 1 1 1 1 1 0 1 0 1 0 1 1 1 2 1

%e 1 1 2 0 1 0 1 2 1 0 1 1 1 0 1 1 1 1 1 2

%K nonn,tabl

%O 1,1

%A _R. H. Hardin_, Sep 25 2013

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Last modified March 22 15:35 EDT 2023. Contains 361432 sequences. (Running on oeis4.)