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Number of nX4 0..2 arrays with no element unequal to a strict majority of its horizontal and vertical neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.
1

%I #4 Dec 21 2016 10:38:21

%S 6,96,824,5704,37289,226118,1300184,7247300,39307590,208922598,

%T 1091842999,5627866564,28670442976,144606882880,723064505682,

%U 3588186045068,17687435316277,86669983177036,422430114412562

%N Number of nX4 0..2 arrays with no element unequal to a strict majority of its horizontal and vertical neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

%C Column 4 of A279871.

%H R. H. Hardin, <a href="/A279868/b279868.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 24*a(n-1) -240*a(n-2) +1247*a(n-3) -3081*a(n-4) -1161*a(n-5) +33758*a(n-6) -110853*a(n-7) +155250*a(n-8) +90976*a(n-9) -934011*a(n-10) +2215284*a(n-11) -2824813*a(n-12) +1193241*a(n-13) +3174042*a(n-14) -9079122*a(n-15) +16484004*a(n-16) -31151892*a(n-17) +62715437*a(n-18) -112476918*a(n-19) +161558619*a(n-20) -178418860*a(n-21) +149979807*a(n-22) -96387564*a(n-23) +39274647*a(n-24) +48194259*a(n-25) -242347800*a(n-26) +565794600*a(n-27) -906143007*a(n-28) +1075619601*a(n-29) -960814140*a(n-30) +651296568*a(n-31) -304948416*a(n-32) -49741822*a(n-33) +504662025*a(n-34) -1149894549*a(n-35) +1815255210*a(n-36) -2154507081*a(n-37) +1942135617*a(n-38) -1155967783*a(n-39) +121512219*a(n-40) +730147767*a(n-41) -1187533515*a(n-42) +1207089672*a(n-43) -942518064*a(n-44) +611098452*a(n-45) -326931228*a(n-46) +143976978*a(n-47) -52824519*a(n-48) +13675344*a(n-49) -1900008*a(n-50) -183576*a(n-51) +402624*a(n-52) -89856*a(n-53) +6336*a(n-54) -4608*a(n-55) -4608*a(n-56) -512*a(n-57) for n>64

%e Some solutions for n=4

%e ..0..0..1..1. .0..0..0..0. .0..0..0..0. .0..0..1..1. .0..1..1..2

%e ..2..2..1..1. .1..1..0..0. .1..0..0..1. .2..0..1..1. .0..1..1..2

%e ..2..2..1..1. .1..1..1..1. .2..2..0..0. .0..0..0..0. .0..0..0..0

%e ..0..0..1..1. .0..0..2..1. .2..2..0..0. .0..0..1..0. .0..0..2..0

%Y Cf. A279871.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 21 2016