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A202460 Number of (n+2) X 9 binary arrays with consecutive windows of three bits considered as a binary number nondecreasing in every row and column. 1

%I #8 Jun 01 2018 05:26:48

%S 2744,8064,21972,54618,124740,264822,528390,1000023,1808746,3145568,

%T 5286030,8618736,13680954,21202494,32159196,47837493,69911652,

%U 100535440,142450112,199110774,274833336,374964438,506076906,676193475,895041702

%N Number of (n+2) X 9 binary arrays with consecutive windows of three bits considered as a binary number nondecreasing in every row and column.

%C Column 7 of A202461.

%H R. H. Hardin, <a href="/A202460/b202460.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = (1/60480)*n^9 + (1/672)*n^8 + (163/3360)*n^7 + (119/144)*n^6 + (24221/2880)*n^5 + (15553/288)*n^4 + (1671487/7560)*n^3 + (282325/504)*n^2 + (404227/420)*n + 937.

%F Conjectures from _Colin Barker_, Jun 01 2018: (Start)

%F G.f.: x*(2744 - 19376*x + 64812*x^2 - 131502*x^3 + 175860*x^4 - 159456*x^5 + 97542*x^6 - 38691*x^7 + 9010*x^8 - 937*x^9) / (1 - x)^10.

%F a(n) = 10*a(n-1) - 45*a(n-2) + 120*a(n-3) - 210*a(n-4) + 252*a(n-5) - 210*a(n-6) + 120*a(n-7) - 45*a(n-8) + 10*a(n-9) - a(n-10) for n>10.

%F (End)

%e Some solutions for n=4:

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

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

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

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

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

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

%Y Cf. A202461.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 19 2011

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