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A253222 Number of n X 7 nonnegative integer arrays with upper left 0 and lower right its king-move distance away minus 2 and every value within 2 of its king move distance from the upper left and every value increasing by 0 or 1 with every step right, diagonally se or down.

%I A253222 #6 Jul 16 2025 11:35:56
%S A253222 15,81,504,3140,16028,47698,47698,649712,2913793,7415837,14420585,
%T A253222 24015795,36221327,51039931,68471783,88516883,111175231,136446827,
%U A253222 164331671,194829763,227941103,263665691,302003527,342954611,386518943
%N A253222 Number of n X 7 nonnegative integer arrays with upper left 0 and lower right its king-move distance away minus 2 and every value within 2 of its king move distance from the upper left and every value increasing by 0 or 1 with every step right, diagonally se or down.
%C A253222 Column 7 of A253223.
%H A253222 R. H. Hardin, <a href="/A253222/b253222.txt">Table of n, a(n) for n = 1..210</a>
%F A253222 Empirical: a(n) = 1306624*n^2 - 20460244*n + 81385043 for n>12.
%e A253222 Some solutions for n=4
%e A253222 ..0..1..2..2..3..3..4....0..0..1..2..3..3..4....0..0..1..2..3..3..4
%e A253222 ..1..1..2..2..3..4..4....0..1..1..2..3..3..4....0..1..1..2..3..3..4
%e A253222 ..2..2..2..3..3..4..4....1..1..1..2..3..3..4....1..1..2..2..3..4..4
%e A253222 ..2..2..2..3..3..4..4....1..1..1..2..3..3..4....2..2..2..2..3..4..4
%Y A253222 Cf. A253223.
%K A253222 nonn
%O A253222 1,1
%A A253222 _R. H. Hardin_, Dec 29 2014