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 A184032 1/16 the number of (n+1) X 3 0..3 arrays with all 2 X 2 subblocks having the same four values. 1
 28, 40, 61, 103, 181, 337, 637, 1237, 2413, 4765, 9421, 18733, 37261, 74317, 148237, 296077, 591373, 1181965, 2362381, 4723213, 9443341, 18883597, 37761037, 75515917, 151019533, 302026765, 604028941, 1208033293, 2416017421, 4831985677 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 2 of A184039. LINKS R. H. Hardin, Table of n, a(n) for n = 1..200 FORMULA Empirical: a(n) = 3*a(n-1) - 6*a(n-3) + 4*a(n-4). Conjectures from Colin Barker, Apr 10 2018: (Start) G.f.: x*(28 - 44*x - 59*x^2 + 88*x^3) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)). a(n) = 9*2^(n/2-1) + 9*2^(n-1) + 13 for n even. a(n) = 9*2^(n-1) + 3*2^((n+1)/2) + 13 for n odd. (End) EXAMPLE Some solutions for 5 X 3: ..1..2..1....0..1..0....0..1..0....1..3..1....2..1..2....3..2..3....3..2..3 ..0..1..0....2..3..2....1..0..1....1..0..1....3..0..3....0..3..0....2..3..2 ..2..1..2....0..1..0....0..1..0....3..1..3....2..1..2....3..2..3....2..3..2 ..0..1..0....3..2..3....0..1..0....0..1..0....3..0..3....3..0..3....2..3..2 ..2..1..2....1..0..1....0..1..0....1..3..1....1..2..1....2..3..2....2..3..2 CROSSREFS Cf. A184039. Sequence in context: A216594 A324858 A084807 * A047630 A135789 A219882 Adjacent sequences:  A184029 A184030 A184031 * A184033 A184034 A184035 KEYWORD nonn AUTHOR R. H. Hardin, Jan 08 2011 STATUS approved

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Last modified December 7 13:08 EST 2021. Contains 349581 sequences. (Running on oeis4.)