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A224043 Number of 7 X n 0..1 arrays with antidiagonals unimodal and rows and diagonals nondecreasing. 1

%I #8 Aug 26 2018 17:00:20

%S 128,987,2419,4160,6321,9125,12856,17875,24623,33686,45837,62087,

%T 83746,112495,150470,200359,265513,350072,459107,598779,776516,

%U 1001209,1283428,1635659,2072563,2611258,3271625,4076639,5052726,6230147,7643410,9331711

%N Number of 7 X n 0..1 arrays with antidiagonals unimodal and rows and diagonals nondecreasing.

%C Row 7 of A224038.

%H R. H. Hardin, <a href="/A224043/b224043.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = (1/5040)*n^7 + (17/360)*n^5 + (13/24)*n^4 + (5767/720)*n^3 + (1919/24)*n^2 + (37901/70)*n + 143 for n>5.

%F Conjectures from _Colin Barker_, Aug 26 2018: (Start)

%F G.f.: x*(128 - 37*x - 1893*x^2 + 5276*x^3 - 5539*x^4 + 1495*x^5 + 1526*x^6 - 1101*x^7 + 65*x^8 + 155*x^9 - 160*x^10 + 117*x^11 - 31*x^12) / (1 - x)^8.

%F 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>13.

%F (End)

%e Some solutions for n=3:

%e ..0..1..1....0..0..0....1..1..1....0..0..0....1..1..1....0..0..1....0..0..0

%e ..0..0..1....1..1..1....0..1..1....0..1..1....0..1..1....0..1..1....0..0..0

%e ..0..1..1....1..1..1....0..0..1....0..0..1....0..0..1....1..1..1....0..0..0

%e ..1..1..1....1..1..1....0..1..1....0..1..1....0..0..1....0..1..1....0..0..1

%e ..0..1..1....0..1..1....0..0..1....1..1..1....0..0..1....0..1..1....0..1..1

%e ..0..0..1....0..1..1....0..0..0....0..1..1....0..0..0....1..1..1....0..0..1

%e ..0..0..1....0..0..1....0..0..0....0..1..1....0..0..0....0..1..1....0..0..0

%Y Cf. A224038.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 30 2013

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Last modified September 7 04:24 EDT 2024. Contains 375729 sequences. (Running on oeis4.)