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A223945 Number of n X 4 0..1 arrays with diagonals and antidiagonals unimodal and rows nondecreasing. 1
5, 25, 96, 321, 1062, 3645, 12856, 45626, 161604, 571202, 2018635, 7138542, 25257472, 89382635, 316317650, 1119405165, 3961434035, 14019204346, 49613421418, 175580918227, 621378416037, 2199050475783, 7782414885011 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A223949.

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) - 5*a(n-2) - 2*a(n-3) + 7*a(n-4) - 2*a(n-5) - 4*a(n-6) - 61*a(n-7) + 29*a(n-8) + 8*a(n-9) + 8*a(n-10).

Empirical g.f.: x*(5 - 4*x^2 - 24*x^3 - 48*x^4 - 33*x^5 - 19*x^6 + 45*x^7 + 16*x^8 + 8*x^9) / (1 - 5*x + 5*x^2 + 2*x^3 - 7*x^4 + 2*x^5 + 4*x^6 + 61*x^7 - 29*x^8 - 8*x^9 - 8*x^10). - Colin Barker, Aug 24 2018

EXAMPLE

Some solutions for n=3:

..0..0..0..0....0..0..0..0....0..0..0..1....0..1..1..1....1..1..1..1

..0..0..0..1....1..1..1..1....0..0..0..0....0..0..1..1....1..1..1..1

..1..1..1..1....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..1

CROSSREFS

Cf. A223949.

Sequence in context: A126878 A203340 A055343 * A197085 A273747 A201841

Adjacent sequences:  A223942 A223943 A223944 * A223946 A223947 A223948

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 29 2013

STATUS

approved

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Last modified February 26 21:58 EST 2020. Contains 332295 sequences. (Running on oeis4.)