OFFSET
1,1
COMMENTS
Row 3 of A194998.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 24*n - 30 for n>2.
Empirical g.f.: 2*x*(1 + 8*x + 2*x^2 + x^3) / (1 - x)^2. - Colin Barker, May 06 2018
EXAMPLE
Some solutions for n=4:
..2......0......4......1......2......1......4......2......3......1......4
..3.2....1.2....3.2....2.1....1.2....2.3....3.4....1.2....4.3....2.3....3.2
..4.3.4..2.1.0..4.3.4..3.2.3..0.1.2..3.2.3..2.3.4..0.1.0..3.2.1..3.2.1..2.1.0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 07 2011
STATUS
approved