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A223837 Number of n X 7 0..1 arrays with rows and antidiagonals unimodal and columns nondecreasing. 1
29, 239, 926, 2578, 6159, 13582, 28369, 56607, 108282, 199047, 352486, 602938, 998945, 1607388, 2518375, 3850945, 5759652, 8442093, 12147444, 17186068, 23940259, 32876186, 44557101, 59657875, 78980926, 103473603, 134247090 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 7 of A223838.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = (4/315)*n^7 - (1/45)*n^6 + (28/45)*n^5 + (113/72)*n^4 + (2137/180)*n^3 + (14023/360)*n^2 + (13159/140)*n - 339 for n>4.

Conjectures from Colin Barker, Aug 23 2018: (Start)

G.f.: x*(29 + 7*x - 174*x^2 + 238*x^3 + 109*x^4 - 256*x^5 + 45*x^6 + 111*x^7 - 27*x^8 - 26*x^9 + 6*x^10 + 2*x^11) / (1 - x)^8.

a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n>12.

(End)

EXAMPLE

Some solutions for n=3:

..0..0..0..1..1..1..0....0..0..0..0..0..0..0....0..1..0..0..0..0..0

..0..0..1..1..1..1..0....0..0..1..1..0..0..0....0..1..1..1..0..0..0

..1..1..1..1..1..1..1....0..1..1..1..1..1..1....1..1..1..1..1..1..1

CROSSREFS

Cf. A223838.

Sequence in context: A027112 A142095 A140845 * A126426 A126425 A224145

Adjacent sequences:  A223834 A223835 A223836 * A223838 A223839 A223840

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 27 2013

STATUS

approved

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Last modified September 21 00:17 EDT 2019. Contains 327252 sequences. (Running on oeis4.)