OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = n^6 + 6*n^5 + 12*n^4 + (44/3)*n^3 + (23/2)*n^2 + (29/6)*n + 1.
Conjectures from Colin Barker, Jan 22 2019: (Start)
G.f.: x*(51 + 265*x + 391*x^2 + 14*x^3 + 5*x^4 - 7*x^5 + x^6) / (1 - x)^7.
a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7.
(End)
EXAMPLE
Some solutions for n=6:
..0. .0. .0. .0. .1. .5. .6. .4. .4. .1. .2. .3. .5. .2. .4. .5
..5. .4. .1. .3. .5. .4. .2. .2. .3. .2. .4. .2. .1. .0. .2. .5
..4. .6. .4. .5. .0. .6. .2. .5. .1. .5. .3. .6. .5. .2. .1. .2
..5. .5. .4. .0. .5. .5. .2. .3. .4. .5. .4. .5. .5. .4. .2. .6
..3. .3. .6. .2. .0. .0. .0. .0. .1. .5. .1. .5. .2. .1. .5. .2
..3. .3. .3. .4. .5. .2. .3. .0. .4. .3. .6. .5. .0. .6. .2. .4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 26 2016
STATUS
approved