OFFSET
1,1
COMMENTS
Row 7 of A269494.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = n^7 + 7*n^6 + 21*n^5 + 15*n^4 + 7*n^3 + 17*n^2 - n - 1.
Empirical: x*(66 +1081*x +2922*x^2 +903*x^3 -122*x^4 +207*x^5 -18*x^6 +x^7) / (x-1)^8 . - R. J. Mathar, Mar 03 2016
EXAMPLE
Some solutions for n=4
..1. .1. .3. .3. .1. .0. .3. .2. .2. .2. .2. .2. .2. .4. .1. .2
..1. .4. .1. .0. .4. .1. .2. .4. .1. .1. .4. .2. .2. .2. .0. .4
..1. .3. .2. .2. .3. .4. .2. .4. .1. .2. .0. .0. .4. .3. .4. .4
..3. .4. .0. .2. .4. .0. .1. .3. .3. .2. .3. .0. .3. .2. .1. .1
..3. .0. .1. .3. .0. .4. .4. .1. .4. .0. .0. .2. .0. .2. .4. .0
..1. .1. .0. .1. .4. .0. .0. .0. .3. .1. .0. .2. .3. .3. .3. .3
..4. .4. .0. .3. .4. .3. .3. .4. .0. .4. .0. .1. .0. .4. .2. .4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 28 2016
STATUS
approved