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A251133 Number of (n+1) X (4+1) 0..2 arrays with no 2 X 2 subblock having the sum of its diagonal elements greater than the maximum of its antidiagonal elements. 1
919, 2264, 4110, 8008, 14753, 27738, 51679, 97758, 186223, 359276, 699161, 1372028, 2707973, 5368806, 10675899, 21273570, 42448163, 84773896, 169396869, 338610768, 677000585, 1353737746, 2707162679, 5413957638, 10827484663, 21654469188 (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) = 6*a(n-1) - 13*a(n-2) + 10*a(n-3) + 5*a(n-4) - 14*a(n-5) + 9*a(n-6) - 2*a(n-7) for n>10.

Conjectures from Colin Barker, Nov 26 2018: (Start)

G.f.: x*(919 - 3250*x + 2473*x^2 + 3590*x^3 - 7100*x^4 + 3770*x^5 - 165*x^6 - 290*x^7 + 7*x^8 + 2*x^9) / ((1 - x)^5*(1 + x)*(1 - 2*x)).

a(n) = (3063 + 961*(-1)^n + 121*2^(5+n) + 1726*n + 691*n^2 + 146*n^3 + 11*n^4) / 12 for n>3.

(End)

EXAMPLE

Some solutions for n=4:

..0..1..1..2..2....0..0..1..1..2....0..0..0..0..2....0..0..1..0..2

..0..0..0..0..0....1..0..1..0..0....0..0..0..0..2....0..0..1..0..1

..0..0..0..0..0....1..0..1..0..0....0..0..0..0..2....1..0..1..0..1

..0..0..0..0..0....1..0..1..0..0....0..0..0..0..2....2..0..1..0..1

..2..2..1..1..0....1..0..1..0..0....1..0..0..0..1....2..0..1..0..0

CROSSREFS

Column 4 of A251137.

Sequence in context: A084843 A059668 A162870 * A083142 A332191 A068163

Adjacent sequences:  A251130 A251131 A251132 * A251134 A251135 A251136

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 30 2014

STATUS

approved

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Last modified May 31 20:23 EDT 2020. Contains 334748 sequences. (Running on oeis4.)