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%I #4 Jul 14 2016 09:55:38
%S 6,54,146,570,2185,8273,31495,120845,462819,1770014,6774047,25932054,
%T 99241078,379774913,1453487054,5562892365,21289984945,81479806330,
%U 311837664172,1193456060092,4567548672431,17480762283012,66901812670647
%N Number of 4Xn 0..2 arrays with no element equal to any value at offset (0,-1) (-1,-2) or (-2,0) and new values introduced in order 0..2.
%C Row 4 of A275037.
%H R. H. Hardin, <a href="/A275039/b275039.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 5*a(n-1) -9*a(n-2) +19*a(n-3) -9*a(n-4) -9*a(n-5) +87*a(n-6) -46*a(n-7) -84*a(n-8) +7*a(n-9) -59*a(n-10) -45*a(n-11) +31*a(n-12) +23*a(n-13) +4*a(n-14) -a(n-15) -a(n-16) +a(n-17) for n>19
%e Some solutions for n=4
%e ..0..1..0..1. .0..1..2..0. .0..1..2..1. .0..1..2..1. .0..1..0..2
%e ..1..2..1..2. .2..0..2..0. .0..1..2..0. .2..0..1..0. .1..2..1..2
%e ..1..0..2..0. .2..0..1..2. .2..0..1..2. .1..0..1..2. .1..0..2..0
%e ..2..1..0..1. .0..1..0..2. .1..2..0..1. .1..2..0..2. .2..0..2..1
%Y Cf. A275037.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jul 14 2016