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 A205513 Number of (n+1) X 2 0..2 arrays with the number of clockwise edge increases in every 2 X 2 subblock differing from each horizontal or vertical neighbor. 3
 81, 360, 1683, 7572, 35577, 160218, 750426, 3387924, 15834846, 71633088, 334163931, 1514409882, 7052640282, 32013216726, 148862055267, 676669161648, 3142331422251, 14301747527646, 66336358731993, 302253567013566 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 1 of A205520. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 18*a(n-2) +6*a(n-3) +39*a(n-4) -2*a(n-5) -3*a(n-6) -4*a(n-7). Empirical g.f.: 3*x*(27 + 120*x + 75*x^2 + 202*x^3 - 12*x^4 - 18*x^5 - 22*x^6) / (1 - 18*x^2 - 6*x^3 - 39*x^4 + 2*x^5 + 3*x^6 + 4*x^7). - Colin Barker, Feb 23 2018 EXAMPLE Some solutions for n=4: ..1..1....0..1....2..1....2..2....2..1....2..0....1..2....0..0....2..1....2..1 ..1..0....2..1....2..2....2..0....2..2....2..2....2..2....2..1....0..2....1..2 ..2..1....2..2....1..0....2..1....2..2....2..2....1..0....0..1....1..2....1..1 ..2..0....1..0....0..0....0..1....2..1....0..2....1..0....2..0....1..0....1..1 ..1..2....2..2....2..1....2..0....1..2....1..0....2..1....2..0....2..2....1..2 CROSSREFS Cf. A205520. Sequence in context: A205520 A236990 A236058 * A017378 A205736 A237850 Adjacent sequences: A205510 A205511 A205512 * A205514 A205515 A205516 KEYWORD nonn AUTHOR R. H. Hardin, Jan 28 2012 STATUS approved

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Last modified August 8 04:35 EDT 2024. Contains 375018 sequences. (Running on oeis4.)