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 A250640 Number of length n+1 0..2 arrays with the sum of the maximum of each adjacent pair multiplied by some arrangement of +-1 equal to zero. 1
 1, 17, 23, 125, 280, 1061, 2870, 9495, 27507, 86149, 255704, 782393, 2341381, 7090347, 21271463, 64109181, 192439733, 578665211, 1736971814, 5217197093, 15658051930, 47004010481, 141050402559, 423295193635, 1270100996174 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 6*a(n-1) - 3*a(n-2) - 42*a(n-3) + 71*a(n-4) + 56*a(n-5) - 192*a(n-6) + 80*a(n-7) + 77*a(n-8) - 64*a(n-9) + 12*a(n-10). Empirical g.f.: x*(1 + 11*x - 76*x^2 + 80*x^3 + 242*x^4 - 541*x^5 + 201*x^6 + 239*x^7 - 192*x^8 + 36*x^9) / ((1 - x)*(1 - 2*x)*(1 + 2*x)*(1 - 3*x)*(1 - 3*x^2 + x^3)*(1 - 2*x - x^2 + x^3)). - Colin Barker, Nov 15 2018 EXAMPLE Some solutions for n=6: ..1....2....1....2....0....0....1....1....2....1....2....0....0....2....2....0 ..0....1....2....2....2....1....1....0....1....2....2....0....1....2....1....1 ..1....1....1....1....1....1....0....1....0....0....1....1....2....1....0....0 ..0....0....2....0....2....2....1....2....1....2....1....0....0....0....2....1 ..1....1....1....2....0....2....0....0....0....0....0....2....1....1....0....0 ..1....0....2....1....1....2....2....2....0....1....0....2....2....1....0....2 ..0....2....1....0....0....1....0....1....1....0....0....0....2....0....1....0 CROSSREFS Column 2 of A250646. Sequence in context: A100473 A060252 A127924 * A344636 A108260 A062628 Adjacent sequences: A250637 A250638 A250639 * A250641 A250642 A250643 KEYWORD nonn AUTHOR R. H. Hardin, Nov 26 2014 STATUS approved

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Last modified August 5 06:29 EDT 2024. Contains 374935 sequences. (Running on oeis4.)