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Number of nX4 0..2 arrays with no element equal to fewer vertical neighbors than horizontal neighbors, with new values 0..2 introduced in row major order
1

%I #4 Apr 20 2014 12:01:04

%S 4,121,4617,169982,6280325,232173463,8582759752,317280724429,

%T 11729003927933,433589294151366,16028613931818561,592534154813233243,

%U 21904372151717063740,809744915865384534529,29934061758919096085329

%N Number of nX4 0..2 arrays with no element equal to fewer vertical neighbors than horizontal neighbors, with new values 0..2 introduced in row major order

%C Column 4 of A241370

%H R. H. Hardin, <a href="/A241366/b241366.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 39*a(n-1) -89*a(n-2) +700*a(n-3) -7268*a(n-4) +12612*a(n-5) -23904*a(n-6) +125306*a(n-7) -773407*a(n-8) +79505*a(n-9) +3859531*a(n-10) -3389476*a(n-11) -9274781*a(n-12) +92305*a(n-13) +19760919*a(n-14) +25560786*a(n-15) -3646222*a(n-16) -31076228*a(n-17) -38721450*a(n-18) -14157300*a(n-19) +16466073*a(n-20) +30488603*a(n-21) +16120777*a(n-22) +778176*a(n-23) -4523626*a(n-24) -3303044*a(n-25) -267592*a(n-26) -1363088*a(n-27) -220864*a(n-28) +213504*a(n-29) -47104*a(n-30) +98304*a(n-31)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 20 2014