A238148 - OEIS

%I #5 Feb 18 2014 08:48:02

%S 256,1608,10664,72584,499560,3342416,22488016,152285824,1043035504,

%T 6998475712,47273279296,319462663168,2181201937664,14658851660800,

%U 99259562449664,669930900621824,4565506277964288,30712312453320704

%N Number of (n+1)X(1+1) 0..3 arrays with the maximum plus the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one

%C Column 1 of A238155

%H R. H. Hardin, <a href="/A238148/b238148.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 1728*a(n-4) +17152*a(n-6) -2064*a(n-8) -513920*a(n-10) -1449280*a(n-12) -772864*a(n-14) +601600*a(n-16) +334848*a(n-18) -331776*a(n-20) for n>21

%e Some solutions for n=4

%e ..0..2....1..1....1..0....3..2....0..3....0..1....2..1....0..3....2..3....2..0

%e ..0..2....0..3....0..2....3..2....3..2....2..0....0..0....2..3....0..2....0..3

%e ..1..3....2..0....2..1....2..2....0..2....0..2....2..0....0..1....2..1....2..3

%e ..1..1....2..1....1..0....0..2....1..2....3..0....0..1....0..3....0..3....0..1

%e ..2..1....0..0....3..0....3..0....1..1....0..1....3..1....2..1....3..2....3..1

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 18 2014