OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 30*a(n-1) - 356*a(n-2) + 2064*a(n-3) - 5618*a(n-4) + 4356*a(n-5) + 4964*a(n-6) + 480*a(n-7) - 143*a(n-8) - 6*a(n-9).
Empirical g.f.: x*(7 - 161*x + 1365*x^2 - 4923*x^3 + 5405*x^4 + 4143*x^5 + 253*x^6 - 111*x^7 - 4*x^8) / ((1 - 6*x)*(1 - 24*x + 212*x^2 - 792*x^3 + 866*x^4 + 840*x^5 + 76*x^6 - 24*x^7 - x^8)). Colin Barker, Jan 24 2019
EXAMPLE
Some solutions for n=6:
..3. .0. .0. .3. .5. .4. .6. .1. .2. .5. .4. .3. .1. .0. .0. .3
..6. .3. .0. .0. .0. .3. .3. .5. .1. .5. .4. .5. .0. .0. .1. .6
..3. .5. .1. .5. .3. .4. .3. .2. .0. .1. .3. .2. .0. .1. .1. .1
..3. .2. .3. .6. .6. .1. .5. .3. .0. .6. .1. .0. .2. .0. .1. .3
..0. .6. .5. .3. .6. .0. .6. .6. .6. .2. .5. .0. .0. .2. .2. .1
..4. .4. .0. .0. .1. .4. .3. .0. .0. .4. .1. .2. .0. .5. .5. .3
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 01 2016
STATUS
approved