cp's OEIS Frontend

A207172 Number of 4 X n 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 0 1 vertically.

%I A207172 #8 Jun 20 2018 09:45:47
%S A207172 8,64,168,603,1612,3952,11452,32021,84300,231616,641775,1736910,
%T A207172 4732822,12996466,35450695,96651608,264382416,722256895,1971272340,
%U A207172 5385783204,14714016328,40180554949,109749174712,299799902720,818831131779
%N A207172 Number of 4 X n 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 0 1 vertically.
%C A207172 Row 4 of A207169.
%H A207172 R. H. Hardin, <a href="/A207172/b207172.txt">Table of n, a(n) for n = 1..210</a>
%F A207172 Empirical: a(n) = a(n-1) + 13*a(n-3) + 3*a(n-4) + 3*a(n-5) - 27*a(n-6) - 18*a(n-7) + 27*a(n-9) for n>11.
%F A207172 Empirical g.f.: x*(8 + 56*x + 104*x^2 + 331*x^3 + 153*x^4 - 60*x^5 - 819*x^6 - 828*x^7 - 54*x^8 + 837*x^9 + 324*x^10) / ((1 - x - 13*x^3 - 3*x^4 - 3*x^5 + 27*x^6 + 18*x^7 - 27*x^9)). - _Colin Barker_, Jun 20 2018
%e A207172 Some solutions for n=4:
%e A207172 ..1..0..0..1....1..1..0..0....1..1..1..1....0..1..0..0....0..0..1..1
%e A207172 ..0..1..1..1....0..0..1..0....0..1..1..1....0..1..0..0....0..1..0..0
%e A207172 ..0..0..1..1....0..0..1..0....0..1..1..0....0..1..0..0....0..1..0..0
%e A207172 ..0..0..1..0....0..0..1..0....0..0..1..0....0..1..0..0....0..1..0..0
%Y A207172 Cf. A207169.
%K A207172 nonn
%O A207172 1,1
%A A207172 _R. H. Hardin_, Feb 15 2012