OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) + 28*a(n-2) - 78*a(n-3) - 264*a(n-4) + 296*a(n-5) + 527*a(n-6) - 252*a(n-7) - 324*a(n-8).
Empirical g.f.: x*(16 + 25*x - 267*x^2 - 104*x^3 + 691*x^4 + 275*x^5 - 576*x^6 - 324*x^7) / (1 - 2*x - 16*x^2 + 7*x^3 + 18*x^4)^2. - Colin Barker, Jan 19 2019
EXAMPLE
Some solutions for n=4:
..0..1..0..1. .1..0..1..0. .0..0..0..1. .0..0..0..1. .0..0..1..1
..0..1..0..1. .0..0..0..1. .1..0..0..1. .0..0..0..1. .1..0..0..0
..0..0..0..1. .1..0..0..0. .0..0..0..0. .0..1..0..0. .1..0..1..0
..1..1..0..1. .0..0..0..1. .0..1..0..0. .0..0..0..0. .0..0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 19 2016
STATUS
approved