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A253750 Number of (2+1)X(n+1) 0..2 arrays with every 2X2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically 1
450, 2723, 10182, 29737, 70590, 148134, 298760, 587522, 1126853, 2134789, 4034824, 7609993, 14320586, 26934197, 50677637, 95365268, 179465371, 337787639, 635898370, 1197229227, 2254216671, 4244626838, 7992870420, 15051425511 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 2 of A253749

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) -10*a(n-2) +12*a(n-3) -9*a(n-4) -5*a(n-5) +25*a(n-6) -35*a(n-7) +33*a(n-8) -15*a(n-9) -15*a(n-10) +33*a(n-11) -35*a(n-12) +25*a(n-13) -5*a(n-14) -9*a(n-15) +12*a(n-16) -10*a(n-17) +5*a(n-18) -a(n-19) for n>25

EXAMPLE

Some solutions for n=4

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

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

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

CROSSREFS

Sequence in context: A079659 A304511 A202197 * A253743 A253369 A253376

Adjacent sequences:  A253747 A253748 A253749 * A253751 A253752 A253753

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 11 2015

STATUS

approved

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Last modified August 4 16:18 EDT 2021. Contains 346447 sequences. (Running on oeis4.)