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A235186 T(n,k) is the number of (n+1) X (k+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings). 9
72, 212, 212, 576, 560, 576, 1696, 1400, 1400, 1696, 4656, 3796, 3240, 3796, 4656, 13736, 9780, 8224, 8224, 9780, 13736, 38064, 27080, 19952, 19584, 19952, 27080, 38064, 112504, 71244, 52328, 45128, 45128, 52328, 71244, 112504, 314448, 200164 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..284

FORMULA

Empirical for column k (the k=4..7 recurrence works also for k=1..3; apparently all rows and columns satisfy the same order 27 recurrence):

k=1: a(n) = 16*a(n-2) -65*a(n-4) +14*a(n-6).

k=2: [order 18].

k=3: [order 26].

k=4..7: [same order 27 recurrence].

EXAMPLE

Table starts

72 212 576 1696 4656 13736 38064 112504 314448

212 560 1400 3796 9780 27080 71244 200164 535384

576 1400 3240 8224 19952 52328 131120 352000 903544

1696 3796 8224 19584 45128 112432 270056 694680 1719360

4656 9780 19952 45128 99096 236376 545768 1351904 3234336

13736 27080 52328 112432 236376 540368 1204056 2877232 6679048

38064 71244 131120 270056 545768 1204056 2598040 6019088 13595968

112504 200164 352000 694680 1351904 2877232 6019088 13521264 29758464

314448 535384 903544 1719360 3234336 6679048 13595968 29758464 64019304

930968 1520236 2468016 4527576 8236464 16488928 32649376 69567168 146227600

Some solutions for n=4, k=4:

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

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

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

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

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

CROSSREFS

Sequence in context: A033693 A250786 A302886 * A235179 A204492 A204485

Adjacent sequences: A235183 A235184 A235185 * A235187 A235188 A235189

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Jan 04 2014

STATUS

approved

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Last modified March 30 21:40 EDT 2023. Contains 361623 sequences. (Running on oeis4.)