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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

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

Adjacent sequences:  A250955 A250956 A250957 * A250959 A250960 A250961

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 29 2014

STATUS

approved

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Last modified June 25 03:59 EDT 2022. Contains 354835 sequences. (Running on oeis4.)