A210271 - OEIS

%I #5 Mar 31 2012 12:37:32

%S 2130,113248,6028871,321050788,17097482699,910532241954,

%T 48490791961375,2582399328204990,137526868179029404,

%U 7324056952893265933,390046040465491252479,20772082296310330599391,1106226850689067938595724

%N Half the number of (n+1)X4 0..2 arrays with every 2X2 subblock having two or three distinct clockwise edge differences

%C Column 3 of A210276

%H R. H. Hardin, <a href="/A210271/b210271.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 48*a(n-1) +480*a(n-2) -9807*a(n-3) -58253*a(n-4) +657082*a(n-5) +2138431*a(n-6) -18778839*a(n-7) -19795420*a(n-8) +235514744*a(n-9) -62769938*a(n-10) -1259927930*a(n-11) +1276469157*a(n-12) +2637995603*a(n-13) -4298139072*a(n-14) -1484220465*a(n-15) +5231313990*a(n-16) -949603112*a(n-17) -2426962356*a(n-18) +931229528*a(n-19) +400609008*a(n-20) -188316850*a(n-21) -12522776*a(n-22) +5412968*a(n-23) -237208*a(n-24) -448*a(n-25)

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 19 2012