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 A203884 Number of (n+1) X 6 0..6 arrays with every 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements. 1
 18193357, 6601376089, 2880436707253, 1337957259758497, 632382967906147549, 300614697430789927465, 143131084226139999444805, 68183470583835920750899441, 32485295368125261340573143277 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All terms == 49 (mod 294). - Robert Israel, Jul 09 2019 LINKS R. H. Hardin, Table of n, a(n) for n = 1..193 Robert Israel, Maple-assisted proof of empirical formula FORMULA Empirical: a(n) = 565*a(n-1) -26916*a(n-2) -8476092*a(n-3) +587809224*a(n-4) -6796290096*a(n-5) -158295697632*a(n-6) +2605874815296*a(n-7) -2681418764160*a(n-8) -55173588410880*a(n-9) +65536012915200*a(n-10) +108491436288000*a(n-11) -105573943296000*a(n-12). Empirical formula verified: see link. - Robert Israel, Jul 09 2019 EXAMPLE Some solutions for n=4 ..2..3..3..6..6..5....0..5..2..5..0..1....5..3..0..6..4..5....6..5..6..3..0..2 ..4..2..3..3..6..6....2..0..5..3..5..0....2..5..3..0..6..4....2..6..5..6..3..0 ..2..6..2..3..3..6....3..2..0..5..5..5....2..2..5..3..0..6....5..2..6..6..6..3 ..6..3..6..2..3..3....3..3..2..0..5..0....2..2..2..5..3..0....4..5..2..6..1..6 ..6..6..4..6..2..3....4..3..3..2..0..1....3..2..4..2..5..3....0..4..5..2..6..3 CROSSREFS Column 5 of A203887. Sequence in context: A271445 A073032 A222977 * A209959 A140171 A185854 Adjacent sequences: A203881 A203882 A203883 * A203885 A203886 A203887 KEYWORD nonn AUTHOR R. H. Hardin, Jan 07 2012 STATUS approved

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Last modified May 23 22:02 EDT 2024. Contains 372765 sequences. (Running on oeis4.)