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 A219143 Unchanging value maps: number of 2 X n binary arrays indicating the locations of corresponding elements unequal to no horizontal, diagonal or antidiagonal neighbor in a random 0..2 2 X n array. 2
 1, 6, 18, 39, 96, 225, 543, 1293, 3096, 7392, 17673, 42228, 100929, 241197, 576441, 1377606, 3292314, 7868187, 18803964, 44939013, 107398431, 256668285, 613403916, 1465955712, 3503443917, 8372776200, 20009848437, 47820940581, 114285841233 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Row 2 of A219142. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 2*a(n-1) + a(n-2) - a(n-3) + 2*a(n-4) for n>5. Empirical g.f.: x*(1 + 4*x + 5*x^2 - 2*x^3 + 4*x^4) / (1 - 2*x - x^2 + x^3 - 2*x^4). - Colin Barker, Mar 11 2018 EXAMPLE Some solutions for n=3: ..1..0..0....0..0..0....0..0..1....0..0..1....0..0..1....1..0..1....1..1..1 ..0..0..1....1..0..0....1..0..0....1..0..1....0..0..0....0..0..0....1..1..1 CROSSREFS Cf. A219142. Sequence in context: A271252 A271541 A035489 * A122061 A299256 A002411 Adjacent sequences:  A219140 A219141 A219142 * A219144 A219145 A219146 KEYWORD nonn AUTHOR R. H. Hardin, Nov 12 2012 STATUS approved

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Last modified December 15 04:23 EST 2019. Contains 329991 sequences. (Running on oeis4.)