OFFSET
1,1
COMMENTS
Column 3 of A222894.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..108
FORMULA
Empirical: a(n) = 211*a(n-1) - 9385*a(n-2) + 110913*a(n-3) - 253890*a(n-4) for n>6.
Conjectures from Colin Barker, Aug 16 2018: (Start)
G.f.: x*(3 - 599*x + 21972*x^2 - 138229*x^3 - 495045*x^4 + 558558*x^5) / ((1 - 3*x)*(1 - 14*x)*(1 - 39*x)*(1 - 155*x)).
a(n) = 3^n + 5*2^(n-1)*7^(n-2) + 14*5^(n-3)*31^(n-2) + 10*39^(n-2) for n>2.
(End)
EXAMPLE
Some solutions for n=3:
..0..1..2....0..1..1....0..1..2....0..1..2....0..1..2....0..1..2....0..1..2
..3..4..5....0..2..2....3..4..5....3..4..2....2..1..0....3..1..2....3..4..5
..2..0..5....3..3..0....1..6..7....2..0..3....3..4..4....2..0..4....1..4..5
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 08 2013
STATUS
approved