[seqfan] Vaguely Self-Referential "Number of Zero Neighbors"
Ron Hardin
rhhardin at att.net
Sun Oct 9 20:15:11 CEST 2011
http://oeis.org/A197049 thru http://oeis.org/A197054,
T(n,k)=Number of nXk 0..4 arrays with each element equal to the number of its
horizontal and vertical zero neighbors
Some solutions for n=6 k=4
..0..2..1..0....0..2..0..1....2..0..2..0....0..3..0..2....0..2..1..0
..2..0..1..2....1..1..1..1....0..2..1..1....2..0..4..0....3..0..1..2
..1..1..2..0....1..0..2..0....2..1..0..2....1..2..0..2....0..3..1..0
..0..3..0..3....1..1..1..1....0..2..2..0....0..1..1..1....2..0..1..2
..3..0..4..0....0..3..0..2....3..0..1..2....1..1..1..0....1..1..2..0
..0..3..0..2....2..0..3..0....0..2..1..0....1..0..1..1....0..2..0..2
might be simple enough for an analytical attack, sort of like tiling I suppose.
The columns T(.,k) have linear recurrences that are not horrible.
rhhardin at mindspring.com
rhhardin at att.net (either)
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