OFFSET
1,4
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 7*a(n-1) - 19*a(n-2) + 31*a(n-3) - 52*a(n-4) + 82*a(n-5) - 84*a(n-6) + 84*a(n-7) - 96*a(n-8) + 56*a(n-9) - 32*a(n-10) + 32*a(n-11).
Empirical g.f.: x*(1 - 7*x + 19*x^2 - 23*x^3 + 20*x^4 - 10*x^5 - 40*x^6 + 44*x^7 - 48*x^8 + 96*x^9) / ((1 - 2*x)^2*(1 - x - 2*x^3)^3). - Colin Barker, Feb 10 2019
EXAMPLE
All solutions for n=4:
..0..1. .0..0. .0..1. .0..0. .0..1. .0..0. .0..1. .0..0
..0..0. .1..1. .0..0. .0..1. .1..1. .1..1. .1..1. .1..0
..1..1. .0..1. .1..1. .1..1. .0..0. .1..0. .0..0. .1..1
..0..1. .0..0. .1..0. .0..0. .0..1. .0..0. .1..0. .0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 07 2016
STATUS
approved