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%I #9 Jun 10 2014 03:55:05
%S 5,23,36,67,133,256,455,931,1830,3565,7001,13872,27433,54401,108164,
%T 215285,428869,855426,1707759,3411577,6819860,13640635,27294311,
%U 54635604,109402661,219127235,438997334,879659285,1762952379,3533677212
%N Number of n X 4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,0,1,3,4 for x=0,1,2,3,4.
%C Every 0 is next to 0 2's, every 1 is next to 1 0's, every 2 is next to 2 1's, every 3 is next to 3 3's, every 4 is next to 4 4's.
%C Column 4 of A195978.
%H R. H. Hardin, <a href="/A195974/b195974.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = 4*a(n-1) -7*a(n-2) +13*a(n-3) -17*a(n-4) +9*a(n-5) -7*a(n-6) -11*a(n-7) +28*a(n-8) -20*a(n-9) +37*a(n-10) -7*a(n-11) +11*a(n-13) -41*a(n-14) +14*a(n-15) -32*a(n-16) +19*a(n-18) -14*a(n-19) +30*a(n-20) -10*a(n-21) +9*a(n-22) +7*a(n-23) -9*a(n-24) +10*a(n-25) -11*a(n-26) +3*a(n-28) -4*a(n-29) +a(n-30) -2*a(n-31) -2*a(n-32).
%e Some solutions for n=5:
%e ..2..1..0..1....2..1..1..2....2..1..1..0....2..1..0..1....0..1..1..1
%e ..1..1..0..1....1..0..0..1....1..0..1..1....1..1..1..2....1..1..0..0
%e ..0..1..1..1....2..1..1..2....1..0..1..1....0..0..1..2....1..1..1..1
%e ..0..1..1..0....2..1..1..2....1..1..1..0....1..1..1..1....0..0..1..1
%e ..0..1..1..0....1..0..0..1....0..1..1..0....2..1..0..0....1..1..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_, Sep 25 2011
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