OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 14*a(n-1) - 42*a(n-2) -49*a(n-3).
Empirical g.f.: 8*x*(1 - 6*x - 6*x^2) / ((1 - 7*x)*(1 - 7*x - 7*x^2)). - Colin Barker, Jan 29 2019
EXAMPLE
Some solutions for n=5:
..4. .2. .0. .1. .2. .0. .2. .7. .4. .3. .1. .0. .7. .5. .5. .6
..3. .3. .0. .1. .2. .5. .0. .1. .7. .1. .0. .5. .1. .2. .1. .6
..4. .2. .6. .0. .6. .5. .0. .1. .1. .5. .3. .2. .5. .6. .7. .6
..3. .0. .1. .4. .4. .1. .7. .5. .3. .3. .3. .4. .3. .1. .1. .5
..5. .1. .5. .1. .0. .4. .5. .5. .0. .1. .3. .0. .1. .1. .2. .7
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 04 2016
STATUS
approved