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A235239 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 6, with no adjacent elements equal (constant stress tilted 1X1 tilings) 9
120, 420, 420, 1328, 1288, 1328, 4652, 3688, 3688, 4652, 14944, 11728, 9656, 11728, 14944, 52468, 34916, 28400, 28400, 34916, 52468, 170864, 113940, 78824, 77368, 78824, 113940, 170864, 601100, 348876, 241456, 201676, 201676, 241456, 348876 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Table starts

.....120......420.....1328.....4652....14944.....52468....170864....601100

.....420.....1288.....3688....11728....34916....113940....348876...1158552

....1328.....3688.....9656....28400....78824....241456....698304...2200992

....4652....11728....28400....77368...201676....580668...1593940...4773744

...14944....34916....78824...201676...496520...1355796...3548456..10155532

...52468...113940...241456...580668..1355796...3512000...8787924..24042932

..170864...348876...698304..1593940..3548456...8787924..21123784..55565636

..601100..1158552..2200992..4773744.10155532..24042932..55565636.140450408

.1980544..3626376..6566416.13619216.27803624..63316120.141304528.345065744

.6979348.12193672.21133848.41986384.82397748.180522036.389137436.917415816

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..198

FORMULA

Empirical for column k (the k=4..6 recurrence works also for k=1..3; apparently all rows and columns satisfy the same order 41 recurrence):

k=1: [linear recurrence of order 8]

k=2: [order 28]

k=3: [order 40]

k=4..6: [same order 41 recurrence]

EXAMPLE

Some solutions for n=4 k=4

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

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

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

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

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

CROSSREFS

Sequence in context: A273509 A147983 A307933 * A337469 A235232 A304284

Adjacent sequences:  A235236 A235237 A235238 * A235240 A235241 A235242

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Jan 05 2014

STATUS

approved

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Last modified June 17 17:39 EDT 2021. Contains 345085 sequences. (Running on oeis4.)