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A258552 Number of (n+1) X (6+1) 0..1 arrays with every 2 X 2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically. 1
988, 683, 1917, 3314, 6662, 10854, 16942, 24300, 33844, 45166, 59274, 75580, 95044, 117306, 143422, 172852, 206604, 244366, 287242, 334740, 387916, 446506, 511662, 582940, 661444, 746958, 840682, 942220, 1052724, 1172026, 1301374, 1440420 (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>14.

Empirical g.f.: x*(988 - 3269*x + 5113*x^2 - 4208*x^3 + 2176*x^4 + 374*x^5 - 2954*x^6 + 2530*x^7 - 1622*x^8 + 1571*x^9 - 743*x^10 + 82*x^11 + 6*x^12 + 4*x^13) / ((1 - x)^5*(1 + x)*(1 + x^2)). - Colin Barker, Dec 22 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Column 6 of A258554.

Sequence in context: A221128 A045733 A250490 * A258559 A235762 A235545

Adjacent sequences:  A258549 A258550 A258551 * A258553 A258554 A258555

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 03 2015

STATUS

approved

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Last modified September 20 20:15 EDT 2021. Contains 347590 sequences. (Running on oeis4.)