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A273968
T(n,k)=Number of nXk 0..3 arrays with no three equal values forming an isosceles triangle, and new values introduced in 0..3 order.
4
1, 2, 2, 5, 10, 5, 15, 105, 105, 15, 51, 1264, 1946, 1264, 51, 187, 13045, 24587, 24587, 13045, 187, 715, 136063, 211121, 49534, 211121, 136063, 715, 2795, 1273961, 2116450, 36817, 36817, 2116450, 1273961, 2795, 11051, 11936399, 15084593, 40569
OFFSET
1,2
COMMENTS
Table starts
......1..........2..........5....15.....51.....187......715......2795.....11051
......2.........10........105..1264..13045..136063..1273961..11936399..95697853
......5........105.......1946.24587.211121.2116450.15084593.112714143.511843593
.....15.......1264......24587.49534..36817...40569....36570.....90627.....89429
.....51......13045.....211121.36817....356......10........0.........0
....187.....136063....2116450.40569.....10.......0........0
....715....1273961...15084593.36570......0.......0
...2795...11936399..112714143.90627......0
..11051...95697853..511843593.89429
..43947..800561388.2841058530
.175275.5824237329
.700075
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = 7*a(n-1) -14*a(n-2) +8*a(n-3)
EXAMPLE
Some solutions for n=4 k=4
..0..0..1..2. .0..1..2..1. .0..1..0..2. .0..0..1..0. .0..0..1..1
..3..1..0..0. .0..3..2..3. .3..3..3..2. .2..3..3..3. .2..1..2..0
..3..1..3..3. .0..3..2..3. .1..2..2..1. .3..2..1..1. .3..1..3..0
..0..2..1..2. .2..1..0..0. .0..1..0..1. .1..0..2..2. .3..1..3..2
CROSSREFS
Column 1 is A007581(n-1).
Sequence in context: A193899 A334017 A208567 * A273964 A223062 A208788
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Jun 05 2016
STATUS
approved