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A220430
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 vertical neighbors in a random 0..3 nXk array
3
1, 1, 1, 2, 6, 2, 4, 23, 23, 4, 7, 94, 236, 94, 7, 12, 380, 2103, 2103, 380, 12, 21, 1494, 18366, 40412, 18366, 1494, 21, 37, 5939, 155250, 735555, 735555, 155250, 5939, 37, 65, 23398, 1286012, 12702453, 26927902, 12702453, 1286012, 23398, 65, 114, 92317
OFFSET
1,4
COMMENTS
Table starts
..1.....1.......2........4........7.......12........21.......37....65.114
..1.....6......23.......94......380.....1494......5939....23398.92317
..2....23.....236.....2103....18366...155250...1286012.10530541
..4....94....2103....40412...735555.12702453.213282872
..7...380...18366...735555.26927902
.12..1494..155250.12702453
.21..5939.1286012
.37.23398
.65
LINKS
EXAMPLE
Some solutions for n=3 k=4
..1..1..0..0....1..0..0..0....1..0..1..0....1..0..0..0....1..1..1..0
..0..0..1..0....1..0..0..1....1..0..0..0....1..0..1..0....0..0..0..0
..0..1..0..0....1..0..1..1....0..1..1..0....0..0..0..1....0..1..1..1
CROSSREFS
Column 1 is A005251(n+1)
Column 2 is A220372
Sequence in context: A085193 A220242 A220375 * A220279 A221188 A220532
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin Dec 14 2012
STATUS
approved