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 A242543 Number of length n+3 0..2 arrays with no four elements in a row with pattern aabb (possibly a=b) and new values 0..2 introduced in 0..2 order 1
 12, 32, 88, 242, 660, 1800, 4920, 13448, 36736, 100352, 274176, 749088, 2046528, 5591168, 15275392, 41733248, 114017280, 311500800, 851036160, 2325074432, 6352221184, 17354590208, 47413622784, 129536428032, 353900101632 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 2 of A242549 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 2*a(n-1) +4*a(n-3) +4*a(n-4). Empirical: G.f.: -2*x*(6+4*x+12*x^2+9*x^3) / ( (2*x^2+2*x-1)*(2*x^2+1) ). - R. J. Mathar, May 18 2014 EXAMPLE Some solutions for n=4 ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0 ..0....1....1....1....1....1....1....1....0....0....1....1....0....0....1....1 ..1....1....0....2....0....0....1....1....0....1....0....0....1....1....0....0 ..2....1....0....1....0....2....2....0....1....2....0....2....0....0....1....2 ..1....2....0....0....2....0....0....1....2....0....1....0....0....0....0....1 ..1....1....1....1....0....1....2....0....2....0....2....0....0....2....0....1 ..0....2....0....2....1....1....0....0....1....1....1....1....1....1....0....2 CROSSREFS Sequence in context: A188183 A183682 A243027 * A194644 A068381 A143238 Adjacent sequences: A242540 A242541 A242542 * A242544 A242545 A242546 KEYWORD nonn AUTHOR R. H. Hardin, May 17 2014 STATUS approved

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Last modified October 3 16:48 EDT 2023. Contains 365868 sequences. (Running on oeis4.)