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A235270
Number of (n+1) X (n+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5 (constant-stress 1 X 1 tilings).
0
40, 208, 632, 2344, 6232, 20440, 51800, 160888, 401560, 1215928, 3032792, 9077944, 22776472, 67860280
OFFSET
1,1
COMMENTS
Diagonal of A235280.
FORMULA
Empirical: a(n) = a(n-1) +23*a(n-2) -23*a(n-3) -200*a(n-4) +200*a(n-5) +820*a(n-6) -820*a(n-7) -1584*a(n-8) +1584*a(n-9) +1152*a(n-10) -1152*a(n-11) [see A235280 for an assumption].
EXAMPLE
Some solutions for n=4:
4 1 4 2 4 4 1 3 1 4 2 4 1 4 1 0 3 0 2 0
0 2 0 3 0 1 3 0 3 1 4 1 3 1 3 3 1 3 0 3
4 1 4 2 4 4 1 3 1 4 2 4 1 4 1 0 3 0 2 0
1 3 1 4 1 1 3 0 3 1 3 0 2 0 2 4 2 4 1 4
4 1 4 2 4 3 0 2 0 3 2 4 1 4 1 0 3 0 2 0
CROSSREFS
Sequence in context: A187379 A077818 A247405 * A181637 A111176 A072108
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 05 2014
STATUS
approved