1,3

Diagonal of A266081.

Table of n, a(n) for n=1..11.

All solutions for n=4

..0..2..3..2....0..0..0..0....0..0..0..0....2..3..2..0....0..0..0..0

..0..3..4..3....2..3..2..0....0..0..0..0....3..4..3..0....0..2..3..2

..0..2..3..2....3..4..3..0....0..0..0..0....2..3..2..0....0..3..4..3

..0..0..0..0....2..3..2..0....0..0..0..0....0..0..0..0....0..2..3..2

Cf. A266081.

Sequence in context: A092659 A002352 A042647 * A041273 A256623 A047169

Adjacent sequences: A266072 A266073 A266074 * A266076 A266077 A266078

nonn

R. H. Hardin, Dec 20 2015

approved