A207662 - OEIS

%I #5 Mar 31 2012 12:37:18

%S 9,81,198,870,3358,12040,47320,182192,676396,2611234,9988846,37623896,

%T 144190134,550120868,2085006194,7964169488,30353664882,115358871282,

%U 439963965434,1676145338780,6377929104862,24307253165970,92589759354554

%N Number of 4Xn 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 1 0 0 vertically

%C Row 4 of A207661

%H R. H. Hardin, <a href="/A207662/b207662.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +2*a(n-2) +45*a(n-3) -13*a(n-4) -13*a(n-5) -450*a(n-6) -7*a(n-7) +119*a(n-8) +1406*a(n-9) +299*a(n-10) -560*a(n-11) -796*a(n-12) -402*a(n-13) -232*a(n-14) -1784*a(n-15) +797*a(n-16) +1473*a(n-17) +418*a(n-18) -221*a(n-19) -95*a(n-20) +35*a(n-21) -234*a(n-22) -9*a(n-23) +45*a(n-24) +4*a(n-25) -3*a(n-26) for n>29

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 19 2012