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Number of (6+1)X(n+1) 0..1 arrays with each row divisible by 3 and column not divisible by 3, read as a binary number with top and left being the most significant bits.
1

%I #4 Sep 22 2015 09:37:38

%S 85,468,61965,2353338,220808869,15231780324,1326209720893,

%T 106936631502210,9144003145262805,767032051328412588,

%U 65294836634705229805,5531730973453989808938,470372064891909511000069

%N Number of (6+1)X(n+1) 0..1 arrays with each row divisible by 3 and column not divisible by 3, read as a binary number with top and left being the most significant bits.

%C Row 6 of A262420.

%H R. H. Hardin, <a href="/A262425/b262425.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 85*a(n-1) +3026*a(n-2) -257210*a(n-3) -2725780*a(n-4) +231691300*a(n-5) +1042604066*a(n-6) -88621345610*a(n-7) -184834243867*a(n-8) +15710910728695*a(n-9) +16148556399500*a(n-10) -1372627293957500*a(n-11) -690707626945552*a(n-12) +58710148290371920*a(n-13) +13366198928883008*a(n-14) -1136126908955055680*a(n-15) -92117546962355200*a(n-16) +7829991491800192000*a(n-17)

%e Some solutions for n=3

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

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

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

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

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

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

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

%Y Cf. A262420.

%K nonn

%O 1,1

%A _R. H. Hardin_, Sep 22 2015