A253362 - OEIS

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A253362

Number of (n+2) X (3+2) 0..1 arrays with every 2 X 2 and 3 X 3 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally and vertically.

560, 960, 2992, 5280, 13800, 27072, 63496, 130464, 297288, 612480, 1410760, 2875104, 6716232, 13589568, 31922056, 64500000, 151450440, 306332928, 718070344, 1453854816, 3404870472, 6895922880, 16148448520, 32703297696

(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) = 7*a(n-2) - 15*a(n-4) + 17*a(n-6) + 16*a(n-8) for n>11.

Empirical g.f.: 8*x*(70 + 120*x - 116*x^2 - 180*x^3 + 157*x^4 + 564*x^5 + 282*x^6 + 480*x^7 - x^8 + 24*x^9 - 36*x^10) / (1 - 7*x^2 + 15*x^4 - 17*x^6 - 16*x^8). - Colin Barker, Dec 11 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

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

CROSSREFS

Column 3 of A253367.

Sequence in context: A234263 A100987 A100971 * A217986 A260290 A249839

Adjacent sequences: A253359 A253360 A253361 * A253363 A253364 A253365

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 30 2014

STATUS

approved