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Number of lower triangles of an (n+1)X(n+1) 0..6 array with new values introduced in row major order 0..6 and no element equal to any horizontal, diagonal, antidiagonal or vertical neighbor
1

%I #5 Mar 31 2012 12:36:22

%S 1,10,1530,1587724,6012771932,76835222989340,3302081001560127592,

%T 477232970093526846547868,231946991234978104864701810980,

%U 379107829075672054750390251800219732

%N Number of lower triangles of an (n+1)X(n+1) 0..6 array with new values introduced in row major order 0..6 and no element equal to any horizontal, diagonal, antidiagonal or vertical neighbor

%C Column 6 of A194794

%H R. H. Hardin, <a href="/A194792/b194792.txt">Table of n, a(n) for n = 1..12</a>

%e Some solutions for 4X4

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

%e ..1.2......1.2......1.2......1.2......1.2......1.2......1.2......1.2

%e ..0.3.0....3.4.5....3.4.5....3.0.4....3.4.0....3.4.5....3.4.1....3.4.5

%e ..1.4.2.4..1.6.3.4..0.2.3.0..4.1.3.0..5.6.2.6..1.6.0.2..5.6.3.6..6.0.1.2

%K nonn

%O 1,2

%A _R. H. Hardin_ Sep 03 2011