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 A319323 a(n) is the number of column convex polyiamonds with n cells. 1
 2, 3, 6, 14, 36, 94, 246, 645, 1682, 4367, 11312, 29261, 75654, 195607, 505794, 1307977, 3382628, 8748288, 22625594, 58516858, 151343298, 391422104, 1012341602 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A polyiamond is column convex if the intersection of its interior with any vertical line through the centers of the cells is connected. LINKS Adam Gruber, Java program to count lattice animals. EXAMPLE The only septiamonds that are not column convex are four rotations/reflections of a "7" shape. So a(7) = A001420(7) - 4 = 246. CROSSREFS Cf. A001420 (fixed polyiamonds), A238823 (row convex polyiamonds). Sequence in context: A246640 A080408 A275774 * A341630 A001420 A337186 Adjacent sequences:  A319320 A319321 A319322 * A319324 A319325 A319326 KEYWORD nonn,more AUTHOR David Bevan, Sep 27 2018 STATUS approved

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Last modified April 17 10:38 EDT 2021. Contains 343064 sequences. (Running on oeis4.)