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.

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

Author

R. H. Hardin, Jun 05 2016

Keywords

• nonn
• tabl

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

Examples

			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
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..82

Crossrefs

Column 1 is A007581(n-1).

Formula

Empirical for column k:

k=1: a(n) = 7*a(n-1) -14*a(n-2) +8*a(n-3)