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 A221589 Equals one maps: number of n X 4 binary arrays indicating the locations of corresponding elements equal to exactly one of their king-move neighbors in a random 0..3 n X 4 array. 1
 8, 180, 3760, 64324, 1043774, 16758008, 268358624, 4294659968, 68718247424, 1099506710528, 17592166375424, 281474898034688, 4503599312666624, 72057592779112448, 1152921499571585024, 18446744053568503808 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 4 of A221590. LINKS R. H. Hardin, Table of n, a(n) for n = 1..92 FORMULA Empirical: a(n) = 20*a(n-1) -64*a(n-2) for n>6. Conjectures from Colin Barker, Aug 09 2018: (Start) G.f.: 2*x*(4 + 10*x + 336*x^2 + 322*x^3 - 1033*x^4 - 368*x^5) / ((1 - 4*x)*(1 - 16*x)). a(n) = 16^n - 2401*2^(2*n-9) for n>4. (End) EXAMPLE Some solutions for n=3. ..1..0..0..1....0..0..0..0....0..0..0..1....0..0..1..1....0..0..0..1 ..0..0..1..1....0..0..0..1....1..0..0..1....0..1..1..1....1..1..1..0 ..0..1..1..0....0..1..0..0....0..1..1..0....0..0..0..1....1..0..1..0 CROSSREFS Cf. A221590. Sequence in context: A299662 A300255 A108552 * A317486 A360340 A060593 Adjacent sequences: A221586 A221587 A221588 * A221590 A221591 A221592 KEYWORD nonn AUTHOR R. H. Hardin, Jan 20 2013 STATUS approved

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Last modified December 2 04:14 EST 2023. Contains 367506 sequences. (Running on oeis4.)