A260923 - OEIS

%I #4 Aug 04 2015 07:35:52

%S 186,279,896,2208,4522,10617,25690,58606,134296,314471,729920,1686078,

%T 3909750,9081515,21033032,48765365,113054330,262238504,607643220,

%U 1409411303,3266491942,7576260468,17557722330,40724481666,94379231110

%N Number of (n+2)X(4+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00010101 00101011 or 01010101

%C Column 4 of A260927

%H R. H. Hardin, <a href="/A260923/b260923.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-2) +18*a(n-4) +32*a(n-6) -7*a(n-8) -33*a(n-10) +13*a(n-12) +25*a(n-14) -28*a(n-16) +9*a(n-18) -a(n-20) for n>22

%e Some solutions for n=4

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

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

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

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

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

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

%Y Cf. A260927

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 04 2015