A207444 - OEIS

%I #5 Mar 31 2012 12:37:17

%S 9,81,333,1360,6092,25689,105690,439332,1821924,7521414,31063445,

%T 128325745,529821580,2187257369,9030334421,37280871533,153905038835,

%U 635365800266,2622977336044,10828351058245,44702329730212

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

%C Row 4 of A207442

%H R. H. Hardin, <a href="/A207444/b207444.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) -4*a(n-2) +21*a(n-3) -78*a(n-4) -31*a(n-5) -41*a(n-6) +475*a(n-7) +568*a(n-8) -94*a(n-9) -2370*a(n-10) -2473*a(n-11) +670*a(n-12) +6654*a(n-13) +6859*a(n-14) -1652*a(n-15) -11383*a(n-16) -11186*a(n-17) +818*a(n-18) +11923*a(n-19) +11553*a(n-20) +1019*a(n-21) -6760*a(n-22) -7392*a(n-23) -1944*a(n-24) +1915*a(n-25) +2670*a(n-26) +1090*a(n-27) -64*a(n-28) -529*a(n-29) -259*a(n-30) -53*a(n-31) +46*a(n-32) +24*a(n-33) +8*a(n-34) -4*a(n-35)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 17 2012