A261287 - OEIS

%I #4 Aug 14 2015 07:14:25

%S 96,133,271,504,1086,2104,4715,9080,20093,38864,86229,166296,368773,

%T 712284,1579561,3049076,6762309,13056148,28953755,55898492,123967937,

%U 239336000,530772749,1024728804,2272547259,4387441960,9730031919

%N Number of (n+2)X(3+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00010101 or 01010101.

%C Column 3 of A261292.

%H R. H. Hardin, <a href="/A261287/b261287.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-2) +9*a(n-4) +4*a(n-6) -4*a(n-8) +6*a(n-10) -8*a(n-12) -a(n-16) +3*a(n-18) +4*a(n-20) -4*a(n-22) for n>26

%e Some solutions for n=4

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

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

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

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

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

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

%Y Cf. A261292.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 14 2015