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A235239
T(n,k) is the number of (n+1) X (k+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 6, with no adjacent elements equal (constant-stress tilted 1 X 1 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
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
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
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Jan 05 2014
STATUS
approved