cp's OEIS Frontend

A207025 Number of 2 X n 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.

%I A207025 #10 Feb 17 2018 15:59:23
%S A207025 4,16,36,81,169,324,625,1156,2116,3844,6889,12321,21904,38809,68644,
%T A207025 121104,213444,375769,660969,1162084,2042041,3587236,6300100,11062276,
%U A207025 19421649,34093921,59845696,105042001,184362084,323568144,567868900
%N A207025 Number of 2 X n 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.
%C A207025 Row 2 of A207024.
%H A207025 R. H. Hardin, <a href="/A207025/b207025.txt">Table of n, a(n) for n = 1..210</a>
%F A207025 Empirical: a(n) = 2*a(n-1) + a(n-2) - a(n-3) - 4*a(n-4) + 2*a(n-5) + a(n-7) + a(n-9) - a(n-10).
%F A207025 Empirical g.f.: x*(4 + 8*x - 3*x^3 + 3*x^4 - 3*x^5 + x^6 - x^7 + x^8 - x^9) / ((1 - x)*(1 - 2*x + x^2 - x^3)*(1 + x - x^3)*(1 - x^2 - x^3)). - _Colin Barker_, Feb 17 2018
%e A207025 Some solutions for n=4:
%e A207025   1 1 1 1    1 1 1 1    1 0 0 1    0 0 1 0    0 1 0 0
%e A207025   0 1 0 1    1 1 1 1    0 1 0 0    0 1 0 1    0 0 1 0
%K A207025 nonn
%O A207025 1,1
%A A207025 _R. H. Hardin_, Feb 14 2012