A261261 - OEIS

%I #4 Aug 13 2015 06:37:01

%S 166,232,690,1918,4350,10382,26072,63964,155288,379950,931560,2278454,

%T 5570500,13629422,33349058,81580648,199570734,488243484,1194455224,

%U 2922102016,7148645416,17488560724,42784191822,104667572730,256059752954

%N Number of (n+2)X(4+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00010101 00100101 or 01010101.

%C Column 4 of A261265.

%H R. H. Hardin, <a href="/A261261/b261261.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +5*a(n-3) +4*a(n-4) +8*a(n-5) +7*a(n-6) +7*a(n-7) +5*a(n-8) -5*a(n-9) -8*a(n-10) -7*a(n-11) -5*a(n-12) -a(n-13) +a(n-14) +a(n-15) +a(n-16) for n>17

%e Some solutions for n=4

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

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

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

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

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

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

%Y Cf. A261265.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 13 2015