OFFSET
1,2
COMMENTS
Column 6 of A229510.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 50*a(n-1) -715*a(n-2) +324*a(n-3) +50175*a(n-4) -180630*a(n-5) -940491*a(n-6) +4556250*a(n-7) +2329155*a(n-8) -27398736*a(n-9) +13286025*a(n-10) +47829690*a(n-11) -43046721*a(n-12) for n>13.
Empirical g.f.: 192*x^2*(40 - 812*x + 2005*x^2 + 40851*x^3 - 164547*x^4 - 625725*x^5 + 3177063*x^6 + 1119015*x^7 - 16522785*x^8 + 8109396*x^9 + 26926344*x^10 - 23914845*x^11) / ((1 - 25*x + 90*x^2 - 81*x^3)^2*(1 - 45*x^2 - 81*x^3)^2). - Colin Barker, Jun 16 2017
EXAMPLE
Some solutions for n=3
..0..1..2..0..2..0....0..1..2..0..2..0....0..1..2..2..1..2....0..1..2..1..2..1
..0..1..2..0..2..0....2..1..2..0..2..1....2..0..0..0..0..0....2..1..2..0..0..1
..0..0..2..0..1..1....0..0..2..0..0..0....2..1..2..2..2..1....0..1..1..1..2..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 25 2013
STATUS
approved