A250497 - OEIS

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A250497

Number of (n+2)X(1+2) 0..1 arrays with nondecreasing medians of every three consecutive values in every row and column

512, 2744, 13824, 68921, 314432, 1367631, 5832000, 24137569, 97336000, 385828352, 1505060136, 5783534875, 21952000000, 82426462208, 306454670488, 1129412837944, 4129885013184, 14994306423179, 54087346107432

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 1 of A250504

LINKS

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

FORMULA

Empirical: a(n) = 8*a(n-1) -20*a(n-2) +44*a(n-3) -190*a(n-4) +292*a(n-5) -242*a(n-6) +1552*a(n-7) -933*a(n-8) -728*a(n-9) -7846*a(n-10) -2828*a(n-11) +2191*a(n-12) +22952*a(n-13) +13106*a(n-14) -556*a(n-15) -37208*a(n-16) -18168*a(n-17) +6972*a(n-18) +33492*a(n-19) -4164*a(n-20) -5916*a(n-21) -10326*a(n-22) +9744*a(n-23) -1676*a(n-24) +5224*a(n-25) -6310*a(n-26) +2776*a(n-27) -2345*a(n-28) +2396*a(n-29) -1876*a(n-30) +1244*a(n-31) -1086*a(n-32) +704*a(n-33) -410*a(n-34) +212*a(n-35) -109*a(n-36) +40*a(n-37) -14*a(n-38) +4*a(n-39) -a(n-40)

EXAMPLE

Some solutions for n=4

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

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

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

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

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

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

CROSSREFS

Sequence in context: A250826 A250504 A250820 * A254260 A254306 A258530

Adjacent sequences: A250494 A250495 A250496 * A250498 A250499 A250500

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 24 2014

STATUS

approved