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 A256728 Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum zero and no antidiagonal sum three. 1
 384, 2304, 13056, 73984, 413440, 2310400, 12865280, 71639296, 398552832, 2217279744, 12332535552, 68593705216, 381495652096, 2121753477376, 11800309124864, 65628404490496, 364996358434560, 2029949420601600 (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-1) - 56*a(n-3) + 64*a(n-4). Empirical g.f.: 128*x*(3 - 3*x - 24*x^2 + 32*x^3) / ((1 - 7*x + 8*x^2)*(1 - 8*x^2)). - Colin Barker, Dec 20 2018 EXAMPLE Some solutions for n=4: ..1..0..1....1..0..0....1..0..1....1..1..0....0..1..0....0..0..0....1..1..0 ..0..1..0....0..0..1....1..0..0....1..1..1....0..1..0....1..1..1....1..1..0 ..0..0..1....1..1..0....0..1..0....1..0..1....1..0..0....0..1..0....0..0..0 ..1..1..1....0..0..0....1..0..1....1..0..0....0..0..1....0..1..0....1..1..0 ..0..0..0....1..0..0....1..1..1....0..1..0....0..1..0....0..0..1....0..0..1 ..1..1..1....1..0..1....0..0..1....0..0..0....0..0..1....0..1..1....1..1..0 CROSSREFS Column 1 of A256735. Sequence in context: A134175 A233886 A256735 * A236029 A252904 A252899 Adjacent sequences: A256725 A256726 A256727 * A256729 A256730 A256731 KEYWORD nonn AUTHOR R. H. Hardin, Apr 09 2015 STATUS approved

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Last modified February 22 20:29 EST 2024. Contains 370264 sequences. (Running on oeis4.)