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 A261705 Number of (n+2)X(2+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000101 or 00000111. 1

%I #4 Aug 28 2015 20:10:49

%S 76,134,270,462,892,1751,3299,6324,12389,23874,46352,90232,175147,

%T 340107,662278,1287201,2502792,4868654,9469734,18415483,35823639,

%U 69677328,135524601,263610130,512755352,997337880,1939945931,3773395523

%N Number of (n+2)X(2+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000101 or 00000111.

%C Column 2 of A261709.

%H R. H. Hardin, <a href="/A261705/b261705.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +a(n-2) -a(n-3) -6*a(n-5) +4*a(n-6) -5*a(n-7) +2*a(n-8) +11*a(n-9) -3*a(n-10) -2*a(n-12) -6*a(n-14) +4*a(n-15) for n>17

%e Some solutions for n=7

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

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

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

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

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

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

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

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

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

%Y Cf. A261709.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 28 2015

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Last modified March 2 02:30 EST 2024. Contains 370447 sequences. (Running on oeis4.)