OFFSET
1,2
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) + 16*a(n-5) - 16*a(n-6) + 32*a(n-7) - 64*a(n-10).
Empirical g.f.: x*(1 + 2*x^3 - 4*x^4 + 8*x^5 - 16*x^8) / (1 - 2*x - 16*x^5 + 16*x^6 - 32*x^7 + 64*x^10). - Colin Barker, Jan 08 2019
EXAMPLE
Some solutions for n=4:
..1..2..3..7..8....1..5..3..4..8....1..5..3..7..8....1..5..6..4..8
..0.10.11.12..4....6.10..0..9..2....0.10..2.12..4....0.10..2..3.13
..5..6.13.14..9...11.12.13.14..7...11..6.13.14..9...11.12..7.14..9
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 18 2015
STATUS
approved