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 A234352 Number of non-equivalent (mod D_3) ways to arrange 4 indistinguishable points on a triangular grid of side n so that no three points are collinear. 4
 2, 24, 153, 713, 2557, 7661, 20055, 47153, 101821, 205322, 390580, 707708, 1229969, 2060777, 3344487 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,1 COMMENTS Column 4 of triangle A234350. Without the restriction "non-equivalent (mod D_3)" the numbers are given by A194132. LINKS EXAMPLE There are a(3) = 2 non-equivalent ways to arrange 4 indistinguishable points (x) on a triangular grid of side 3:     x         .    x x       x x   . x .     x . x CROSSREFS Cf. A234350, A194132 Arranging 3 points: A234351 Arranging 5 points: A234353 Arranging 6 points: A234354 Sequence in context: A163752 A035600 A189247 * A241623 A288443 A108476 Adjacent sequences:  A234349 A234350 A234351 * A234353 A234354 A234355 KEYWORD nonn,more AUTHOR Heinrich Ludwig, Dec 30 2013 EXTENSIONS a(14)-a(17) from Heinrich Ludwig, Apr 19 2016 STATUS approved

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Last modified August 11 06:25 EDT 2020. Contains 336422 sequences. (Running on oeis4.)