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A258551 Number of (n+1) X (5+1) 0..1 arrays with every 2 X 2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically. 1
480, 506, 1403, 2509, 5070, 8339, 12940, 18630, 26240, 35386, 46687, 59945, 76039, 94633, 116394, 141172, 169894, 202272, 239021, 280039, 326301, 377567, 434600, 497346, 566828, 642854, 726235, 816965, 916115, 1023541, 1140102, 1265840 (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) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - 4*a(n-5) + 6*a(n-6) - 4*a(n-7) + a(n-8) for n>13.

Empirical g.f.: x*(480 - 1414*x + 2259*x^2 - 1987*x^3 + 1428*x^4 - 579*x^5 - 888*x^6 + 1120*x^7 - 834*x^8 + 778*x^9 - 368*x^10 + 50*x^11 + 3*x^12) / ((1 - x)^5*(1 + x)*(1 + x^2)). - Colin Barker, Dec 21 2018

EXAMPLE

Some solutions for n=4:

..0..0..0..0..0..0....0..0..0..0..0..0....0..0..0..0..0..0....0..0..0..0..0..0

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

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

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

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

CROSSREFS

Column 5 of A258554.

Sequence in context: A262222 A115157 A019287 * A257415 A179667 A108876

Adjacent sequences:  A258548 A258549 A258550 * A258552 A258553 A258554

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 03 2015

STATUS

approved

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Last modified July 30 14:56 EDT 2021. Contains 346359 sequences. (Running on oeis4.)