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Number of nX7 nonnegative integer arrays with upper left 0 and lower right its king-move distance away minus 3 and every value increasing by 0 or 1 with every step right, diagonally se or down
1

%I #4 Dec 25 2014 19:31:15

%S 20,231,2902,33533,309990,2327062,14697256,541365583,9617848524,

%T 90094114144,499454404412,1875291094664,5288570216780,12109231279152,

%U 23836473347284,42007667355832,68169527721372,103870860371584

%N Number of nX7 nonnegative integer arrays with upper left 0 and lower right its king-move distance away minus 3 and every value increasing by 0 or 1 with every step right, diagonally se or down

%C Column 7 of A253011

%H R. H. Hardin, <a href="/A253010/b253010.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = (774604193792/3)*n^3 - 8398560300416*n^2 + (277091586550828/3)*n - 343375674454152 for n>18

%e Some solutions for n=6

%e ..0..0..0..0..0..0..0....0..0..0..0..1..1..2....0..0..0..0..0..0..1

%e ..0..0..1..1..1..1..1....0..0..0..1..1..2..2....0..0..0..0..1..1..1

%e ..0..0..1..1..1..1..2....0..0..0..1..1..2..3....0..0..0..1..1..1..2

%e ..0..0..1..1..1..1..2....0..0..0..1..1..2..3....0..0..1..1..1..2..2

%e ..0..1..1..1..2..2..2....0..1..1..1..1..2..3....0..0..1..1..1..2..2

%e ..0..1..2..2..2..3..3....0..1..1..2..2..2..3....0..0..1..1..2..2..3

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 25 2014