A253813 - OEIS

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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

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