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 #5 Mar 31 2012 12:36:56
%S 21,1640,89610,5390325,314688054,18550312526,1089970014327,
%T 64114204398028,3769915844080995,221699388876599524,
%U 13037021233036033635,766652822812020772883,45083423150083817466414,2651159090798112000786121
%N Number of nX7 binary arrays with every 1 immediately preceded by 0 to the left or above
%C Column 7 of A203362
%H R. H. Hardin, <a href="/A203361/b203361.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 21*a(n-1) +1743*a(n-2) +25515*a(n-3) +156938*a(n-4) +213951*a(n-5) -1636533*a(n-6) -3128592*a(n-7) +23316551*a(n-8) +17066544*a(n-9) -199519590*a(n-10) +291472395*a(n-11) -22194350*a(n-12) -173766021*a(n-13) +129035841*a(n-14) -33578772*a(n-15) -2885164*a(n-16) +4086456*a(n-17) -689631*a(n-18) -24273*a(n-19) +4320*a(n-20) for n>21
%e Some solutions for n=3
%e ..0..1..0..0..1..0..0....0..0..0..0..0..1..0....0..0..1..0..1..0..1
%e ..0..0..1..0..0..1..1....0..1..0..0..0..1..1....0..0..1..0..1..0..1
%e ..0..1..0..1..0..1..0....1..0..1..1..0..1..0....1..1..0..1..0..0..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Dec 31 2011