OFFSET
1,1
COMMENTS
Column 3 of A222871.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 42*a(n-1) - 117*a(n-2) for n>4.
Conjectures from Colin Barker, Aug 16 2018: (Start)
G.f.: x*(3 - 92*x - 261*x^2 + 234*x^3) / ((1 - 3*x)*(1 - 39*x)).
a(n) = 4*3^(n-1) + 20*39^(n-2) for n>2.
(End)
EXAMPLE
Some solutions for n=3:
..0..0..1....0..1..2....0..1..2....0..1..2....0..1..2....0..1..2....0..1..1
..2..2..3....3..3..4....3..3..0....3..4..5....3..1..0....3..4..2....2..3..4
..4..5..5....1..2..5....2..4..1....1..2..3....4..2..5....5..4..0....1..5..5
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 07 2013
STATUS
approved