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A250958
Number of (n+1) X (1+1) 0..3 arrays with no 2 X 2 subblock having its minimum diagonal element less than its minimum antidiagonal element.
1
170, 1592, 14423, 130025, 1172956, 10588744, 95612685, 863389506, 7796459439, 70402180164, 635731893289, 5740658602219, 51838142971409, 468098406239405, 4226928439879553, 38169162413062088, 344667524042889328
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 16*a(n-1) - 86*a(n-2) + 248*a(n-3) - 397*a(n-4) + 361*a(n-5) - 168*a(n-6) + 36*a(n-7).
Empirical g.f.: x*(170 - 1128*x + 3571*x^2 - 5991*x^3 + 5608*x^4 - 2652*x^5 + 576*x^6) / (1 - 16*x + 86*x^2 - 248*x^3 + 397*x^4 - 361*x^5 + 168*x^6 - 36*x^7). - Colin Barker, Nov 24 2018
EXAMPLE
Some solutions for n=4:
2 1 2 0 1 0 1 1 3 1 0 1 0 0 1 0 2 0 1 2
2 3 3 2 2 3 2 3 2 2 0 0 2 0 2 0 3 1 0 0
0 3 0 0 0 1 0 1 1 3 1 0 1 0 1 0 3 3 3 1
0 0 1 0 0 0 0 0 0 2 3 2 3 3 1 1 2 2 2 2
1 2 0 1 0 3 0 1 0 3 0 1 0 1 2 3 0 1 3 2
CROSSREFS
Column 1 of A250965.
Sequence in context: A259293 A262426 A250965 * A031614 A289648 A187520
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 29 2014
STATUS
approved