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A220328 T(n,k)=Equals two maps: number of nXk binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..1 nXk array.

%I A220328 #6 Jul 23 2025 01:03:47
%S A220328 1,1,1,2,4,1,4,16,12,1,7,48,92,37,1,12,174,572,508,114,1,21,658,4062,
%T A220328 6657,2788,351,1,37,2482,29467,92093,76627,15316,1081,1,65,9229,
%U A220328 213225,1335202,2065264,876714,84196,3329,1,114,33982,1540686,18836493,59893608
%N A220328 T(n,k)=Equals two maps: number of nXk binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..1 nXk array.
%C A220328 Table starts
%C A220328 .1.....1.......2.........4..........7.........12.........21........37
%C A220328 .1.....4......16........48........174........658.......2482......9229
%C A220328 .1....12......92.......572.......4062......29467.....213225...1540686
%C A220328 .1....37.....508......6657......92093....1335202...18836493.265346645
%C A220328 .1...114....2788.....76627....2065264...59893608.1653121774
%C A220328 .1...351...15316....876714...46094354.2680626797
%C A220328 .1..1081...84196..10004541.1026529800
%C A220328 .1..3329..462940.114058230
%C A220328 .1.10252.2545492
%C A220328 .1.31572
%C A220328 .1
%H A220328 R. H. Hardin, <a href="/A220328/b220328.txt">Table of n, a(n) for n = 1..70</a>
%e A220328 Some solutions for n=3 k=4
%e A220328 ..0..0..0..0....0..0..0..0....0..1..0..0....0..0..0..0....0..1..1..1
%e A220328 ..0..0..0..0....1..1..0..0....1..0..1..0....1..1..1..1....0..0..1..1
%e A220328 ..1..0..1..0....1..1..0..0....1..0..1..0....0..1..1..0....0..0..0..0
%Y A220328 Column 2 is A099098
%Y A220328 Row 1 is A005251(n+1)
%K A220328 nonn,tabl
%O A220328 1,4
%A A220328 _R. H. Hardin_ Dec 10 2012