A198621 - OEIS

%I #5 Mar 31 2012 12:36:34

%S 1,3,14,76,488,3521,28009,241590,2223711,21519533,216099699,

%T 2228023793,23394765858,248722671553,2666496996271,28746778089814,

%U 311062415257234,3374225209472645,36661349689794535,398760168220542400

%N Number of nX2 0..5 arrays with values 0..5 introduced in row major order and each element equal to at least one horizontal or vertical neighbor

%C Column 2 of A198627

%H R. H. Hardin, <a href="/A198621/b198621.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = 26*a(n-1) -225*a(n-2) +616*a(n-3) +987*a(n-4) -5730*a(n-5) -1309*a(n-6) +15122*a(n-7) +15401*a(n-8) -20868*a(n-9) -34559*a(n-10) -3370*a(n-11) +29842*a(n-12) +18864*a(n-13) -3196*a(n-14) -9000*a(n-15) -2600*a(n-16)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_ Oct 27 2011