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 A229398 Number of n X 4 0..2 arrays with top left element 0, horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and antidiagonal differences never 0. 1
 8, 34, 153, 711, 3357, 15952, 75965, 362012, 1725628, 8226525, 39219624, 186980973, 891444175, 4250029697, 20262368018, 96602551624, 460560895602, 2195763437529, 10468490114235, 49909423013209, 237947448670976, 1134434841904169 (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) = 9*a(n-1) - 28*a(n-2) + 47*a(n-3) - 55*a(n-4) + 47*a(n-5) - 28*a(n-6) + 9*a(n-7) - a(n-8). Empirical g.f.: x*(1 - x)*(8 - 30*x + 41*x^2 - 49*x^3 + 35*x^4 - 15*x^5 + 2*x^6) / (1 - 9*x + 28*x^2 - 47*x^3 + 55*x^4 - 47*x^5 + 28*x^6 - 9*x^7 + x^8). - Colin Barker, Sep 15 2018 EXAMPLE Some solutions for n=4: ..0..2..1..1....0..2..1..0....0..2..1..0....0..2..2..1....0..2..1..1 ..0..2..2..1....0..2..2..1....0..2..1..0....0..0..2..2....0..0..2..1 ..1..0..2..2....1..0..2..1....0..2..1..1....1..0..0..0....1..1..0..2 ..1..1..0..0....1..0..2..1....0..2..2..1....1..1..1..1....2..1..1..0 CROSSREFS Column 4 of A229402. Sequence in context: A335749 A227330 A252934 * A223015 A222796 A203445 Adjacent sequences:  A229395 A229396 A229397 * A229399 A229400 A229401 KEYWORD nonn AUTHOR R. H. Hardin, Sep 22 2013 STATUS approved

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Last modified July 2 21:48 EDT 2022. Contains 355029 sequences. (Running on oeis4.)