A205604 - OEIS

%I #5 Mar 31 2012 12:37:06

%S 443,9688,229445,5470216,131086803,3128383392,74880118862,

%T 1789102516698,42797416252738,1022912102229384,24463500789654523,

%U 584810372631311890,13984289373326702867,334330210257654099548,7994180856499923543924

%N Number of (n+1)X4 0..3 arrays with every 2X2 subblock having the same number of equal edges as its horizontal neighbors and a different number from its vertical neighbors, and new values 0..3 introduced in row major order

%C Column 3 of A205609

%H R. H. Hardin, <a href="/A205604/b205604.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 471*a(n-2) +3520*a(n-3) -9982*a(n-4) -369876*a(n-5) -1286266*a(n-6) +12652252*a(n-7) +62302467*a(n-8) -172499788*a(n-9) -969353689*a(n-10) +1140886196*a(n-11) +5920757684*a(n-12) -6427855248*a(n-13) -4731229724*a(n-14) +58949652912*a(n-15) -43707104144*a(n-16) -108388914768*a(n-17) +316917783552*a(n-18) -1562540422272*a(n-19) -4852781707392*a(n-20) +2639798305920*a(n-21) +15547627524096*a(n-22) +8515882377216*a(n-23) -8609700003840*a(n-24) -9567761596416*a(n-25) -2412483969024*a(n-26) for n>27

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 29 2012