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 A243723 Number of length n+2 0..4 arrays with no three unequal elements in a row and no three equal elements in a row and new values 0..4 introduced in 0..4 order. 1
 3, 6, 12, 25, 53, 116, 259, 593, 1382, 3281, 7897, 19252, 47391, 117645, 293934, 738341, 1862341, 4713220, 11959211, 30407929, 77440630, 197470825, 504041249, 1287558068, 3291018759, 8415888789, 21529314366, 55091691997, 141006790829 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 4*a(n-1) - 13*a(n-3) + 6*a(n-4) + 8*a(n-5). Empirical g.f.: x*(3 - 6*x - 12*x^2 + 16*x^3 + 13*x^4) / ((1 - 2*x)*(1 - x - x^2)*(1 - x - 4*x^2)). - Colin Barker, Nov 03 2018 EXAMPLE Some solutions for n=6: ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0 ..1....1....1....0....0....1....1....1....0....1....1....1....0....1....1....1 ..1....1....0....1....1....0....0....1....1....1....1....0....1....0....0....1 ..2....2....1....0....1....0....0....0....1....0....2....0....0....1....1....0 ..1....1....1....1....0....1....2....0....0....1....2....2....1....0....0....0 ..2....2....2....0....1....1....2....1....0....1....3....2....0....1....1....2 ..2....2....2....1....1....2....0....1....2....0....2....1....1....0....1....2 ..0....1....0....1....0....2....0....2....0....1....3....2....0....1....2....1 CROSSREFS Column 4 of A243729. Sequence in context: A267539 A243722 A187260 * A243724 A243725 A243726 Adjacent sequences: A243720 A243721 A243722 * A243724 A243725 A243726 KEYWORD nonn AUTHOR R. H. Hardin, Jun 09 2014 STATUS approved

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Last modified November 30 23:40 EST 2023. Contains 367464 sequences. (Running on oeis4.)