OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 184*a(n-1) - 9134*a(n-2) + 61640*a(n-3) - 112225*a(n-4) for n>5.
Empirical g.f.: 60*x*(1 + 108*x - 850*x^2 + 1554*x^3 + 225*x^4) / (1 - 92*x + 335*x^2)^2. - Colin Barker, Jan 28 2019
EXAMPLE
Some solutions for n=2:
..1..2..5. .0..1..4. .4..0..2. .2..4..4. .0..0..4. .5..3..0. .2..0..4
..5..4..1. .2..0..4. .3..0..5. .2..1..5. .4..1..5. .2..1..4. .1..2..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 04 2016
STATUS
approved