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A235319 T(n,k)=Number of (n+1)X(k+1) 0..6 arrays with every 2X2 subblock having its diagonal sum differing from its antidiagonal sum by 7 (constant stress 1X1 tilings) 9
112, 392, 392, 1120, 1120, 1120, 3920, 2744, 2744, 3920, 11776, 8392, 5968, 8392, 11776, 41216, 22568, 16352, 16352, 22568, 41216, 128128, 71896, 40144, 40144, 40144, 71896, 128128, 448448, 206360, 118160, 89600, 89600, 118160, 206360 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Table starts

.....112.....392....1120.....3920....11776....41216...128128....448448

.....392....1120....2744.....8392....22568....71896...206360....675064

....1120....2744....5968....16352....40144...118160...316912....978320

....3920....8392...16352....40144....89600...241600...598976...1723456

...11776...22568...40144....89600...184144...459536..1062832...2873552

...41216...71896..118160...241600...459536..1062832..2291696...5805424

..128128..206360..316912...598976..1062832..2291696..4632208..11046512

..448448..675064..978320..1723456..2873552..5805424.11046512..24862768

.1426432.2026472.2793040..4616960..7275856.13828496.24862768..52954448

.4992512.6751000.8912144.13917952.20859728.37480816.63985520.129456304

Empirical: T(n,k)=Number of (n+1)X(k+1) 0..5+i arrays with every 2X2 subblock having its diagonal sum differing from its antidiagonal sum by 5+2*i (constant stress 1X1 tilings), for i=1..3(..?)

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..260

FORMULA

Empirical for column k (the k=2..6 recurrence also works for k=1; apparently all rows and columns satisfy the same order 18 recurrence):

k=1: a(n) = 28*a(n-2) -252*a(n-4) +720*a(n-6)

k=2..6: [same order 18 recurrence]

EXAMPLE

Some solutions for n=4 k=4

..5..4..6..1..5....2..4..2..4..2....1..6..2..4..2....3..0..3..0..3

..0..6..1..3..0....6..1..6..1..6....4..2..5..0..5....1..5..1..5..1

..4..3..5..0..4....3..5..3..5..3....0..5..1..3..1....5..2..5..2..5

..0..6..1..3..0....5..0..5..0..5....4..2..5..0..5....2..6..2..6..2

..4..3..5..0..4....2..4..2..4..2....1..6..2..4..2....3..0..3..0..3

CROSSREFS

Sequence in context: A270759 A233892 A233885 * A203923 A235312 A203916

Adjacent sequences:  A235316 A235317 A235318 * A235320 A235321 A235322

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Jan 05 2014

STATUS

approved

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Last modified May 25 03:14 EDT 2019. Contains 323539 sequences. (Running on oeis4.)