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A280810 T(n,k)=Number of nXk 0..1 arrays with no element equal to more than two of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. 8
0, 0, 0, 0, 1, 0, 0, 3, 3, 0, 0, 18, 56, 18, 0, 0, 72, 332, 332, 72, 0, 0, 284, 1578, 2146, 1578, 284, 0, 0, 1047, 6540, 9715, 9715, 6540, 1047, 0, 0, 3722, 24490, 37644, 41931, 37644, 24490, 3722, 0, 0, 12816, 86010, 133067, 155560, 155560, 133067, 86010, 12816, 0, 0 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
1,8
COMMENTS
Table starts
.0.....0......0.......0........0........0.........0.........0.........0
.0.....1......3......18.......72......284......1047......3722.....12816
.0.....3.....56.....332.....1578.....6540.....24490.....86010....288426
.0....18....332....2146.....9715....37644....133067....440282...1387898
.0....72...1578....9715....41931...155560....521862...1635481...4878157
.0...284...6540...37644...155560...547197...1736603...5150299..14554327
.0..1047..24490..133067...521862..1736603...5219491..14672850..39446188
.0..3722..86010..440282..1635481..5150299..14672850..39260363.100719254
.0.12816.288426.1387898..4878157.14554327..39446188.100719254.247768745
.0.43077.933792.4213683.14014639.39708623.102668319.251288174.594591866
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = a(n-1)
k=2: [order 18]
k=3: [order 18] for n>24
k=4: [order 28] for n>36
k=5: [order 37] for n>46
k=6: [order 43] for n>53
k=7: [order 49] for n>60
EXAMPLE
Some solutions for n=4 k=4
..0..1..1..1. .0..1..0..0. .0..1..1..0. .0..1..0..0. .0..1..1..0
..0..1..0..1. .0..1..0..1. .0..0..0..1. .1..1..1..0. .1..0..0..1
..1..0..1..0. .1..0..0..0. .1..0..1..0. .0..0..0..1. .0..1..1..1
..1..0..1..1. .1..1..1..1. .1..1..0..0. .1..1..0..0. .0..0..1..0
CROSSREFS
Sequence in context: A199237 A309651 A305541 * A283386 A278385 A245626
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Jan 08 2017
STATUS
approved

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Last modified April 12 07:56 EDT 2024. Contains 371626 sequences. (Running on oeis4.)