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A253813 Number of (n+2)X(1+2) 0..1 arrays with every 3X3 subblock diagonal sum minus antidiagonal median nondecreasing horizontally and vertically 2
512, 2700, 12680, 47816, 178752, 618856, 2201616, 7686444, 27456624, 97621664, 351178392, 1260927472, 4551240904, 16412577588, 59322609368, 214326499116, 775118000256, 2802669569216, 10138358665920, 36671008548568 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A253820

LINKS

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

FORMULA

Empirical: a(n) = 8*a(n-1) -13*a(n-2) -48*a(n-3) +189*a(n-4) -186*a(n-5) -159*a(n-6) +930*a(n-7) -2020*a(n-8) +1910*a(n-9) +440*a(n-10) -3300*a(n-11) +5625*a(n-12) -6150*a(n-13) +3525*a(n-14) -750*a(n-15) -625*a(n-16) +1250*a(n-17) -625*a(n-18)

EXAMPLE

Some solutions for n=4

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

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

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

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

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

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

CROSSREFS

Sequence in context: A254476 A254804 A253820 * A254512 A254819 A254505

Adjacent sequences:  A253810 A253811 A253812 * A253814 A253815 A253816

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 14 2015

STATUS

approved

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Last modified August 2 21:30 EDT 2021. Contains 346429 sequences. (Running on oeis4.)