A261286 - OEIS

%I #4 Aug 14 2015 07:13:41

%S 50,77,133,233,409,743,1361,2469,4485,8183,14901,27091,49293,89729,

%T 163277,297055,540549,983737,1790089,3257319,5927571,10786801,

%U 19628869,35719195,65000021,118283183,215243755,391687275,712769639,1297054417

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

%C Column 2 of A261292.

%H R. H. Hardin, <a href="/A261286/b261286.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +4*a(n-3) -a(n-4) -5*a(n-6) +2*a(n-8) +a(n-9) -a(n-10) -3*a(n-11) +a(n-12) +a(n-13) +a(n-14) -2*a(n-15) -2*a(n-16) for n>17

%e Some solutions for n=4

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

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

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

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

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

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

%Y Cf. A261292.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 14 2015