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A268798 T(n,k)=Number of nXk 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once. 8
0, 3, 3, 12, 22, 12, 36, 78, 78, 36, 96, 234, 248, 234, 96, 240, 652, 950, 950, 652, 240, 576, 1714, 3384, 4800, 3384, 1714, 576, 1344, 4360, 11948, 23994, 23994, 11948, 4360, 1344, 3072, 10820, 41248, 117062, 168740, 117062, 41248, 10820, 3072, 6912, 26366 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Table starts

....0.....3......12.......36.........96.........240...........576

....3....22......78......234........652........1714..........4360

...12....78.....248......950.......3384.......11948.........41248

...36...234.....950.....4800......23994......117062........561116

...96...652....3384....23994.....168740.....1158904.......7801688

..240..1714...11948...117062....1158904....11138352.....104971262

..576..4360...41248...561116....7801688...104971262....1384570516

.1344.10820..140698..2652936...51781418...974000420...17967375416

.3072.26366..474472.12405748..339641264..8927994302..230262982692

.6912.63346.1586038.57490444.2206871084.81031120788.2921020155826

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..637

FORMULA

Empirical for column k:

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

k=2: a(n) = 2*a(n-1) +3*a(n-2) -2*a(n-3) -6*a(n-4) -4*a(n-5) -a(n-6) for n>7

k=3: [order 10] for n>12

k=4: [order 16] for n>19

k=5: [order 26] for n>29

k=6: [order 42] for n>45

k=7: [order 68] for n>71

EXAMPLE

Some solutions for n=4 k=4

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

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

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

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

CROSSREFS

Column 1 is A167667(n-1).

Sequence in context: A290438 A006804 A052533 * A136533 A268639 A192307

Adjacent sequences:  A268795 A268796 A268797 * A268799 A268800 A268801

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Feb 13 2016

STATUS

approved

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Last modified September 16 05:49 EDT 2021. Contains 347469 sequences. (Running on oeis4.)