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 A223764 Number of n X 2 0..1 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing. 4
 4, 12, 28, 56, 101, 169, 267, 403, 586, 826, 1134, 1522, 2003, 2591, 3301, 4149, 5152, 6328, 7696, 9276, 11089, 13157, 15503, 18151, 21126, 24454, 28162, 32278, 36831, 41851, 47369, 53417, 60028, 67236, 75076, 83584, 92797, 102753, 113491, 125051 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 2 of A223770. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = (1/24)*n^4 + (1/4)*n^3 + (35/24)*n^2 + (5/4)*n + 1. Conjectures from Colin Barker, Feb 21 2018: (Start) G.f.: x*(2 - 2*x + x^2)^2 / (1 - x)^5. a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5. (End) EXAMPLE Some solutions for n=3: ..0..0....0..0....0..0....1..0....1..1....0..0....0..1....0..1....0..0....0..1 ..0..0....0..0....1..1....0..1....0..1....1..0....1..1....0..0....1..0....0..1 ..1..1....0..1....1..1....0..0....0..1....0..1....0..1....0..0....1..1....1..0 CROSSREFS Cf. A223770. Sequence in context: A161216 A085622 A011940 * A102653 A102650 A011939 Adjacent sequences:  A223761 A223762 A223763 * A223765 A223766 A223767 KEYWORD nonn AUTHOR R. H. Hardin, Mar 27 2013 STATUS approved

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Last modified April 4 07:32 EDT 2020. Contains 333213 sequences. (Running on oeis4.)