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 A225008 Number of n X 6 0..1 arrays with rows unimodal and columns nondecreasing. 1
 22, 148, 610, 1897, 4900, 11088, 22716, 43065, 76714, 129844, 210574, 329329, 499240, 736576, 1061208, 1497105, 2072862, 2822260, 3784858, 5006617, 6540556, 8447440, 10796500, 13666185, 17144946, 21332052, 26338438, 32287585, 39316432 (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) = (2/45)*n^6 + (8/15)*n^5 + (91/36)*n^4 + 6*n^3 + (1337/180)*n^2 + (67/15)*n + 1. Conjectures from Colin Barker, Sep 05 2018: (Start) G.f.: x*(22 - 6*x + 36*x^2 - 35*x^3 + 21*x^4 - 7*x^5 + x^6) / (1 - x)^7. a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7. (End) EXAMPLE Some solutions for n=3: ..0..1..0..0..0..0....0..0..1..0..0..0....0..0..1..1..1..0....0..0..1..1..0..0 ..0..1..0..0..0..0....0..1..1..1..1..0....0..0..1..1..1..0....0..1..1..1..1..0 ..0..1..1..1..0..0....1..1..1..1..1..0....0..1..1..1..1..1....0..1..1..1..1..0 CROSSREFS Column 6 of A225010. Sequence in context: A159505 A223836 A224144 * A240384 A245380 A271635 Adjacent sequences:  A225005 A225006 A225007 * A225009 A225010 A225011 KEYWORD nonn AUTHOR R. H. Hardin, Apr 23 2013 STATUS approved

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Last modified October 22 03:04 EDT 2019. Contains 328315 sequences. (Running on oeis4.)