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A251127 Number of (n+1) X (7+1) 0..1 arrays with no 2 X 2 subblock having the sum of its diagonal elements greater than the maximum of its antidiagonal elements. 1
354, 510, 680, 938, 1268, 1743, 2420, 3429, 4957, 7321, 11025, 16890, 26241, 41224, 65310, 104116, 166730, 267857, 431290, 695527, 1122859, 1814075, 2932255, 4741268, 7668063, 12403458, 20065220, 32461934, 52519952, 84974211, 137486000 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) - 5*a(n-2) + a(n-3) + 2*a(n-4) - a(n-5) for n>6.
Empirical g.f.: x*(354 - 906*x + 410*x^2 + 414*x^3 - 302*x^4 + 15*x^5) / ((1 - x)^3*(1 - x - x^2)). - Colin Barker, Nov 26 2018
EXAMPLE
Some solutions for n=4:
..0..0..0..0..0..0..0..1....0..0..0..1..0..1..0..1....0..0..0..0..0..0..1..0
..0..0..0..0..0..0..0..1....0..0..0..1..0..1..0..0....0..0..0..0..0..0..1..0
..0..0..0..0..0..0..0..1....0..0..0..1..0..1..0..0....0..0..0..0..0..0..1..0
..1..1..1..1..1..1..1..1....0..0..0..1..0..1..0..0....0..0..0..0..0..0..1..0
..1..0..0..0..0..0..0..0....0..0..0..1..0..1..0..0....1..1..1..1..1..1..1..0
CROSSREFS
Column 7 of A251128.
Sequence in context: A213470 A068684 A270782 * A176197 A157668 A250157
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 30 2014
STATUS
approved

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Last modified July 17 12:34 EDT 2024. Contains 374377 sequences. (Running on oeis4.)