A273964 T(n,k)=Number of nXk 0..3 arrays with no three equal values forming an isosceles right triangle, and new values introduced in 0..3 order.

1, 2, 2, 5, 10, 5, 15, 105, 105, 15, 51, 1264, 2766, 1264, 51, 187, 15418, 49702, 49702, 15418, 187, 715, 188465, 784878, 543906, 784878, 188465, 715, 2795, 2304141, 13322548, 4010258, 4010258, 13322548, 2304141, 2795, 11051, 28171070, 232027264

Offset: 1

Author

R. H. Hardin, Jun 05 2016

Keywords

• nonn
• tabl

Comments

Table starts

.........1.................2...................5............15......51......187

.........2................10.................105..........1264...15418...188465

.........5...............105................2766.........49702..784878.13322548

........15..............1264...............49702........543906.4010258.16365681

........51.............15418..............784878.......4010258.5029904...725420

.......187............188465............13322548......16365681..725420.....2890

.......715...........2304141...........232027264......55643290...30060.......12

......2795..........28171070..........4056338728.....210405148....1337........2

.....11051.........344428103.........70402715640.....904155053......54........0

.....43947........4211086174.......1221782263634....4384022592......11........0

....175275.......51486063258......21228810396872...21350702064.......0........0

....700075......629484802987.....368923543916728..105038486755.......0........0

...2798251.....7696279187803....6410003754557834..514302715276.......0

..11188907....94097130028610..111371494441358332.2558243582787

..44747435..1150461107685501.1935130749075453956

.178973355.14065899352150196

.715860651

Examples

			Some solutions for n=3 k=4
..0..0..1..2. .0..1..2..1. .0..1..2..1. .0..1..0..2. .0..0..1..0
..3..3..2..1. .3..1..2..0. .0..1..3..2. .0..1..0..1. .2..2..1..3
..1..2..3..1. .3..2..1..3. .3..2..1..0. .3..1..3..2. .3..3..2..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..153

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)

k=2: [order 7] for n>8