A234672 T(n,k) is the number of (n+1) X (k+1) 0..7 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).

492, 3816, 3816, 29568, 28860, 29568, 229272, 217968, 217968, 229272, 1778412, 1648188, 1604020, 1648188, 1778412, 13801056, 12470688, 11826092, 11826092, 12470688, 13801056, 107144508, 94430072, 87273500, 85076140, 87273500

Offset

1,1

Comments

Table starts

492 3816 29568 229272 1778412 13801056

3816 28860 217968 1648188 12470688 94430072

29568 217968 1604020 11826092 87273500 644848264

229272 1648188 11826092 85076140 612823800 4421960468

1778412 12470688 87273500 612823800 4310166424 30383174872

13801056 94430072 644848264 4421960468 30383174872

107144508 715532392 4769561472 31951474920

832197192 5425977036 35319420856

6466444032 41174389648

50269824456

Links

R. H. Hardin, Table of n, a(n) for n = 1..60

Formula

Empirical for column k:

k=1: [linear recurrence of order 7].

k=2: [order 31].

Example

Some solutions for n=2, k=4:
  6 0 5 3 4      2 0 6 0 3      4 2 0 0 6      0 2 4 6 3
  4 2 3 5 2      2 4 6 4 3      2 4 6 2 4      0 6 4 2 3
  0 2 7 5 6      4 2 0 2 5      4 2 0 0 6      4 6 0 2 7

Crossrefs

Sequence in context: A229520 A226715 A205819 * A234667 A231455 A007242

Adjacent sequences: A234669 A234670 A234671 * A234673 A234674 A234675

Keyword

nonn,tabl

Author

R. H. Hardin, Dec 29 2013

Status

approved