A232311 Number of (n+1)X(3+1) 0..1 arrays with every element equal to some horizontal or antidiagonal neighbor, with top left element zero.
16, 139, 1202, 10409, 90157, 780922, 6764246, 58591124, 507509767, 4395993154, 38077604237, 329823977717, 2856898655026, 24746138781034, 214348305112232, 1856661207278099, 16082193123986242, 139302170295461137
Offset: 1
Keywords
Examples
Some.solutions.for.n=5 ..0..0..0..0....0..0..1..0....0..0..0..0....0..0..1..0....0..0..0..0 ..0..1..1..1....0..1..0..0....0..0..0..0....1..1..0..0....0..1..1..1 ..0..0..0..0....1..1..1..0....1..1..0..0....1..1..1..0....1..1..1..0 ..1..1..0..0....0..0..0..1....0..0..1..0....1..0..0..1....0..0..0..0 ..1..0..1..1....0..0..1..1....0..1..0..1....0..1..1..0....1..1..1..0 ..1..1..1..1....1..1..1..1....1..1..1..1....1..0..0..0....1..0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 10*a(n-1) -11*a(n-2) -5*a(n-3) -a(n-4).
Empirical: G.f.: -x*(-16+21*x+12*x^2+2*x^3) / ( 1-10*x+11*x^2+5*x^3+x^4 ). - R. J. Mathar, Nov 24 2013
Comments