OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 19*a(n-1) + 16*a(n-2).
Conjectures from Colin Barker, Jan 07 2019: (Start)
G.f.: x*(181 + 128*x) / (1 - 19*x - 16*x^2).
a(n) = (2^(-n)*((19-5*sqrt(17))^n*(-21+4*sqrt(17)) + (21+4*sqrt(17))*(19+5*sqrt(17))^n)) / sqrt(17).
(End)
EXAMPLE
Some solutions for n=3:
..0..2..1..4..3....0..8..1..3..4....7..1..3..2..4....0..2..1..4..3
.12..6..7..9..8...12..5..7..9..2....5.13..0..8..9....5..6.14..9..8
.17.10..5.14.13...17.11.13..6.14...11.10.12..6.14...11.10.12.13..7
.16.15.18.11.19...15.16.10.18.19...15.17.16.19.18...16.15.18.17.19
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 11 2015
STATUS
approved