OFFSET
1,1
COMMENTS
Table starts
...16...39...69..109..181..325..613.1189.2341.4645..9253.18469.36901.73765
...39...72...88..120..192..336..624.1200.2352.4656..9264.18480.36912.73776
...69...88...94..129..201..345..633.1209.2361.4665..9273.18489.36921.73785
..109..120..129..164..236..380..668.1244.2396.4700..9308.18524.36956.73820
..181..192..201..236..308..452..740.1316.2468.4772..9380.18596.37028.73892
..325..336..345..380..452..596..884.1460.2612.4916..9524.18740.37172.74036
..613..624..633..668..740..884.1172.1748.2900.5204..9812.19028.37460.74324
.1189.1200.1209.1244.1316.1460.1748.2324.3476.5780.10388.19604.38036.74900
.2341.2352.2361.2396.2468.2612.2900.3476.4628.6932.11540.20756.39188.76052
.4645.4656.4665.4700.4772.4916.5204.5780.6932.9236.13844.23060.41492.78356
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..1243
FORMULA
Empirical for rows, columns, diagonal: a(n) = 3*a(n-1) -2*a(n-2) for n>5
Empirical for max(n,k)>3: T(n,k) = 9*2^(n-1) + 9*2^(k-1) + c, where c=28 for min(n,k)=1, c=30 for min(n,k)=2, c=21 for min(n,k)=3, c=20 for min(n,k)>3
(no formula for the upper left 3X3 portion)
EXAMPLE
Some solutions for n=6 k=4
..1..1..1..1..1....0..0..0..0..0....0..1..1..1..1....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..0..0....0..0..0..0..0....1..1..1..1..1....0..0..0..0..0
..1..1..1..1..1....1..1..1..1..1....0..0..0..0..0....0..0..0..0..0
..1..1..1..1..1....1..1..1..1..1....0..0..0..0..0....1..1..1..1..1
..1..1..1..1..1....1..1..1..1..1....0..0..0..0..0....0..0..0..0..0
..1..1..1..1..1....0..0..0..0..1....1..1..1..1..1....1..1..1..1..1
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Dec 28 2014
STATUS
approved