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A206470 Number of (n+1)X7 0..2 arrays with every 2X2 subblock having zero permanent.

%I A206470 #7 Jul 22 2025 19:28:20
%S A206470 29241,8963667,356190129,52552339515,3420616959081,377599682448675,
%T A206470 30374762423377761,2996776279527835851,262356222717008105625,
%U A206470 24807486299199737090355,2243325257562176033089041
%N A206470 Number of (n+1)X7 0..2 arrays with every 2X2 subblock having zero permanent.
%C A206470 Column 6 of A206472
%H A206470 R. H. Hardin, <a href="/A206470/b206470.txt">Table of n, a(n) for n = 1..210</a>
%F A206470 Empirical: a(n) = 147*a(n-1) -783720*a(n-3) +22720320*a(n-4) +1208991744*a(n-5) -54468142848*a(n-6) -614613775104*a(n-7) +51672615856128*a(n-8) -95234427260928*a(n-9) -23998259218120704*a(n-10) +201605913386680320*a(n-11) +5689361505992048640*a(n-12) -76294817096637874176*a(n-13) -628017046749267886080*a(n-14) +13195491648030973624320*a(n-15) +14645283042051703701504*a(n-16) -1131405415550428045639680*a(n-17) +2665553144520224318423040*a(n-18) +45873154851254425563955200*a(n-19) -208791793059186748686336000*a(n-20) -694038525930408939356160000*a(n-21) +5010428057070448693739520000*a(n-22) -38126822008840601972244480000*a(n-24) +51697385774699121318297600000*a(n-25)
%e A206470 Some solutions for n=4
%e A206470 ..2..0..2..1..0..2..0....2..0..1..1..0..1..1....0..0..1..2..2..0..0
%e A206470 ..1..0..0..0..0..1..0....1..0..0..0..0..0..0....0..0..0..0..0..0..0
%e A206470 ..0..0..0..0..0..2..0....2..0..0..2..2..1..0....0..2..2..1..2..0..0
%e A206470 ..0..1..1..1..0..1..0....2..0..0..0..0..0..0....0..0..0..0..0..0..1
%e A206470 ..0..0..0..0..0..0..0....0..0..2..1..2..1..0....0..2..2..0..1..0..1
%K A206470 nonn
%O A206470 1,1
%A A206470 _R. H. Hardin_ Feb 08 2012