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A206987 T(n,k)=Number of nXk 0..1 arrays avoiding the patterns 0 1 0 or 1 0 1 in any row, column, diagonal or antidiagonal.

%I A206987 #7 Jul 22 2025 19:53:42
%S A206987 2,4,4,6,16,6,10,36,36,10,16,100,58,100,16,26,256,158,158,256,26,42,
%T A206987 676,420,556,420,676,42,68,1764,1066,1866,1866,1066,1764,68,110,4624,
%U A206987 2754,5804,7500,5804,2754,4624,110,178,12100,7140,18528,27762,27762,18528
%N A206987 T(n,k)=Number of nXk 0..1 arrays avoiding the patterns 0 1 0 or 1 0 1 in any row, column, diagonal or antidiagonal.
%C A206987 Table starts
%C A206987 ..2....4....6....10.....16......26.......42........68.......110........178
%C A206987 ..4...16...36...100....256.....676.....1764......4624.....12100......31684
%C A206987 ..6...36...58...158....420....1066.....2754......7140.....18430......47602
%C A206987 .10..100..158...556...1866....5804....18528.....59888....191484.....612874
%C A206987 .16..256..420..1866...7500...27762...106110....413526...1583234....6065840
%C A206987 .26..676.1066..5804..27762..119224...539576...2511348..11347860...51289536
%C A206987 .42.1764.2754.18528.106110..539576..2926752..16410772..88554260..477698908
%C A206987 .68.4624.7140.59888.413526.2511348.16410772.111202694.721243184.4677018224
%H A206987 R. H. Hardin, <a href="/A206987/b206987.txt">Table of n, a(n) for n = 1..420</a>
%e A206987 Some solutions for n=4 k=3
%e A206987 ..0..1..1....0..0..1....1..1..1....0..0..1....0..1..1....1..1..0....0..1..1
%e A206987 ..0..0..1....1..1..1....1..1..1....1..1..1....1..1..1....1..0..0....1..1..1
%e A206987 ..0..0..0....1..1..1....1..1..1....1..1..1....1..1..1....0..0..0....1..1..1
%e A206987 ..0..0..0....1..1..0....1..1..0....0..1..1....0..0..1....0..0..0....0..0..0
%Y A206987 Column 1 is A006355(n+2)
%K A206987 nonn,tabl
%O A206987 1,1
%A A206987 _R. H. Hardin_ Feb 14 2012