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A186574
T(n,k)=Number of (n+2)X(k+2) 0..7 arrays with every 3X3 subblock commuting with each horizontal and vertical neighbor 3X3 subblock
2
134217728, 40922, 40922, 2175043, 3383, 2175043, 5261909, 16401, 16401, 5261909, 21336430, 339649, 335092, 339649, 21336430, 41303124, 851259, 1406478, 1406478, 851259, 41303124, 62806428, 1119049, 2074892, 17616908, 2074892, 1119049
OFFSET
1,1
COMMENTS
Table starts
.134217728...40922..2175043..5261909..21336430..41303124..62806428..68281222
.....40922....3383....16401...339649....851259...1119049...1236313...1378665
...2175043...16401...335092..1406478...2074892...2236060...2422316...3006844
...5261909..339649..1406478.17616908..20944652..21482140..22417900..25486140
..21336430..851259..2074892.20944652..59508492..60795484..64214956..70996220
..41303124.1119049..2236060.21482140..60795484..69691980..76517148..87955372
..62806428.1236313..2422316.22417900..64214956..76517148..93739724.120920668
..68281222.1378665..3006844.25486140..70996220..87955372.120920668.178672908
.199303510.1968681..6080572.34731516..87664508.120673708.178469852.272599692
.384169510.5163488.15726572.73928044.167497324.228103324.325043020.550844092
LINKS
FORMULA
Empirical, for all columns: a(n)=2*a(n-1)-a(n-2)+7*a(n-3)-14*a(n-4)+7*a(n-5)+7*a(n-6)-7*a(n-7) for n>26,12,11,12,13,14,15 respectively for k=1..7
EXAMPLE
Some solutions for 5X4
..0..0..2..5....0..0..0..4....0..0..4..1....0..0..0..7....0..0..0..2
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..6....0..0..0..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..0..0..0..0....2..0..0..0....0..0..0..0....0..0..0..0....4..0..0..0
..3..4..0..0....7..2..0..0....0..0..0..7....6..0..0..0....0..4..0..0
CROSSREFS
Sequence in context: A251281 A011577 A186573 * A017001 A017073 A017265
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin Feb 23 2011
STATUS
approved