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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
3, 7, 7, 17, 33, 17, 39, 129, 129, 39, 91, 481, 775, 481, 91, 211, 1751, 4193, 4193, 1751, 211, 491, 6433, 23059, 34151, 23059, 6433, 491, 1141, 23507, 124431, 275243, 275243, 124431, 23507, 1141, 2653, 86295, 680991, 2223913, 3336437, 2223913, 680991 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Table starts

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

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

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

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

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

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

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

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

.2653.316099.20206283.1169783337.68219097971.3914741097513.227806404072631

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..179

FORMULA

Empirical for column k:

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

k=2: [order 20].

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

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

EXAMPLE

Some solutions for n=3, k=4:

2 0 1 1 2 0 1 1 1 0 1 1 2 0 2 1 1 0 1 1

1 1 0 1 0 1 1 1 1 1 0 1 0 1 0 1 1 1 2 1

1 1 2 0 1 0 1 2 1 0 1 1 1 0 1 1 1 1 1 2

CROSSREFS

Sequence in context: A240260 A240427 A239047 * A263337 A160994 A113833

Adjacent sequences: A229518 A229519 A229520 * A229522 A229523 A229524

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Sep 25 2013

STATUS

approved

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Last modified February 6 11:36 EST 2023. Contains 360104 sequences. (Running on oeis4.)