Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #10 Jun 12 2018 11:12:55
%S 180,714,2880,12318,53100,230532,1002240,4361064,18980472,82617132,
%T 359622708,1565418528,6814215036,29662110636,129118523304,
%U 562050276348,2446593518052,10649972628456,46359118343628,201800318106108
%N Number of (n+1) X 4 0..2 arrays with the number of clockwise edge increases in every 2 X 2 subblock unequal to the number of counterclockwise edge increases.
%C Column 3 of A205823.
%H R. H. Hardin, <a href="/A205818/b205818.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) + 10*a(n-2) - 13*a(n-3) - 25*a(n-4) + 12*a(n-5) + 18*a(n-6) - 2*a(n-8).
%F Empirical g.f.: 6*x*(30 + 29*x - 177*x^2 - 187*x^3 + 188*x^4 + 197*x^5 - 5*x^6 - 23*x^7) / ((1 - x - x^2)*(1 - 2*x - 11*x^2 + 14*x^4 + 2*x^5 - 2*x^6)). - _Colin Barker_, Jun 12 2018
%e Some solutions for n=4:
%e ..1..0..0..2....0..0..2..2....2..2..2..0....1..1..1..0....1..2..1..1
%e ..1..2..1..2....2..1..1..0....1..0..1..0....2..0..2..2....1..0..0..2
%e ..1..0..1..0....2..0..2..2....1..2..1..2....2..1..1..0....2..2..1..1
%e ..2..0..2..2....1..1..1..0....0..2..0..2....2..0..2..2....1..0..0..2
%e ..2..1..1..0....2..0..2..0....0..1..1..1....2..1..1..0....1..2..1..2
%Y Cf. A205823.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 01 2012