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%I #9 May 06 2018 11:53:46
%S 1024,3151,5428,7705,9982,12259,14536,16813,19090,21367,23644,25921,
%T 28198,30475,32752,35029,37306,39583,41860,44137,46414,48691,50968,
%U 53245,55522,57799,60076,62353,64630,66907,69184,71461,73738,76015,78292,80569
%N Number of lower triangles of a 4 X 4 0..n array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by one or less.
%C Row 4 of A195232.
%H R. H. Hardin, <a href="/A195234/b195234.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = 2277*n - 1403 for n>1.
%F Conjectures from _Colin Barker_, May 06 2018: (Start)
%F G.f.: x*(1024 + 1103*x + 150*x^2) / (1 - x)^2.
%F a(n) = 2*a(n-1) - a(n-2) for n>3.
%F (End)
%e Some solutions for n=4:
%e ..4........3........2........0........2........4........3........0
%e ..3.3......2.2......2.3......1.1......1.1......3.4......2.3......1.1
%e ..4.3.3....2.3.2....2.2.3....2.1.1....0.1.0....3.3.4....3.3.2....2.1.0
%e ..3.3.2.3..3.3.2.3..1.2.2.3..1.2.2.2..1.0.0.1..4.4.3.4..2.2.3.3..1.1.1.0
%Y Cf. A195232.
%K nonn
%O 1,1
%A _R. H. Hardin_, Sep 13 2011
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