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A202883 Number of n X 2 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor. 1
3, 35, 265, 1849, 13345, 96941, 701275, 5071167, 36689027, 265439091, 1920308033, 13892446697, 100505282121, 727107537885, 5260271847715, 38055531396239, 275313438949691, 1991760080088995, 14409424470217081, 104245243244589977 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A202889.

LINKS

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

FORMULA

Empirical: a(n) = 6*a(n-1) +2*a(n-2) +46*a(n-3) +25*a(n-4) +36*a(n-5).

Empirical g.f.: (3 + 17*x + 49*x^2 + 51*x^3 + 36*x^4) / (1 - 6*x - 2*x^2 - 46*x^3 - 25*x^4 - 36*x^5). - Colin Barker, Jun 02 2018

EXAMPLE

Some solutions for n=5:

  2 0   2 1   2 0   0 0   0 0   0 1   2 2   2 1   1 2   2 2

  2 0   2 1   2 2   1 1   0 2   2 2   2 1   2 2   1 2   1 1

  0 2   2 1   2 2   1 0   0 2   0 1   0 0   2 0   1 2   2 1

  0 2   2 0   0 0   2 1   2 2   1 1   2 0   0 1   2 2   2 0

  0 1   1 0   1 1   2 1   2 1   2 2   2 1   1 1   0 1   1 0

CROSSREFS

Cf. A202889.

Sequence in context: A061548 A019273 A271209 * A069448 A121078 A289950

Adjacent sequences:  A202880 A202881 A202882 * A202884 A202885 A202886

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 25 2011

STATUS

approved

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Last modified July 7 16:01 EDT 2020. Contains 335496 sequences. (Running on oeis4.)