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 A210406 Number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock having three or four distinct values, and new values 0..3 introduced in row major order. 1
 7, 78, 864, 9576, 106128, 1176192, 13035456, 144468864, 1601114112, 17744767488, 196661044224, 2179547652096, 24155409051648, 267708662341632, 2966951532036096, 32882019268460544, 364423611069038592 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 1 of A210413. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 10*a(n-1) + 12*a(n-2). Conjectures from Colin Barker, Jul 15 2018: (Start) G.f.: x*(7 + 8*x) / (1 - 10*x - 12*x^2). a(n) = ((5-sqrt(37))^n*(-11+2*sqrt(37)) + (5+sqrt(37))^n*(11+2*sqrt(37))) / (6*sqrt(37)). (End) EXAMPLE Some solutions for n=4: ..0..0....0..0....0..0....0..1....0..0....0..0....0..1....0..0....0..1....0..0 ..1..2....1..2....1..2....0..2....1..2....1..2....0..2....1..2....2..3....1..2 ..0..1....3..1....1..3....2..3....1..3....1..3....1..1....0..1....2..0....3..2 ..1..2....1..2....1..2....0..2....2..1....3..2....3..0....1..2....1..1....0..1 ..0..2....0..1....3..2....3..3....2..3....0..0....1..0....3..3....2..3....0..2 CROSSREFS Cf. A210413. Sequence in context: A210413 A045485 A068621 * A133272 A186657 A079590 Adjacent sequences: A210403 A210404 A210405 * A210407 A210408 A210409 KEYWORD nonn AUTHOR R. H. Hardin, Mar 21 2012 STATUS approved

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Last modified September 25 20:01 EDT 2023. Contains 365649 sequences. (Running on oeis4.)