A253158 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A253158

Number of (n+1) X (7+1) 0..1 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally and vertically.

613, 624, 633, 668, 740, 884, 1172, 1748, 2900, 5204, 9812, 19028, 37460, 74324, 148052, 295508, 590420, 1180244, 2359892, 4719188, 9437780, 18874964, 37749332, 75498068, 150995540, 301990484, 603980372, 1207960148, 2415919700, 4831838804

(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) = 3*a(n-1) - 2*a(n-2) for n>5.

Empirical: a(n) = 9*2^(n-1) + 596 for n>3.

Empirical g.f.: x*(613 - 1215*x - 13*x^2 + 17*x^3 + 2*x^4) / ((1 - x)*(1 - 2*x)). - Colin Barker, Dec 09 2018

EXAMPLE

Some solutions for n=6:

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

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

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

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

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

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

CROSSREFS

Column 7 of A253159.

Sequence in context: A292036 A253434 A253441 * A159641 A100364 A142435

Adjacent sequences: A253155 A253156 A253157 * A253159 A253160 A253161

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 28 2014

STATUS

approved