A205364 - OEIS

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

%S 1976,31848,516364,8539884,143559116,2448719840,42290474776,

%T 737993545372,12988141017436,230145818607660,4100220870678448,

%U 73358893720135520,1316830676835150404,23698058348765945172,427312014589126089788

%N Number of (n+1)X3 0..3 arrays with the number of clockwise edge increases in every 2X2 subblock the same

%C Column 2 of A205370

%H R. H. Hardin, <a href="/A205364/b205364.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 39*a(n-1) -494*a(n-2) +2341*a(n-3) -4372*a(n-4) -2243*a(n-5) +27629*a(n-6) -71364*a(n-7) +132199*a(n-8) -205216*a(n-9) +254720*a(n-10) -262592*a(n-11) +241702*a(n-12) -187260*a(n-13) +118740*a(n-14) -66636*a(n-15) +30712*a(n-16) -10072*a(n-17) +2648*a(n-18) -432*a(n-19) -80*a(n-20) +32*a(n-21)

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 26 2012