A268256 Number of length-(n+1) 0..3 arrays with new repeated values introduced in sequential order starting with zero.

13, 43, 143, 479, 1616, 5492, 18804, 64869, 225483, 789747, 2787100, 9910252, 35501416, 128109313, 465606659, 1704022367, 6278399432, 23282368196, 86873186508, 326055377709, 1230562324251, 4668500002491, 17797745988388

Offset: 1

Author

R. H. Hardin, Jan 29 2016

Keywords

• nonn

Examples

			Some solutions for n=8:
..0....0....1....1....0....2....0....1....2....2....0....0....2....2....3....0
..1....2....2....3....1....3....0....0....0....3....1....3....1....1....0....0
..3....0....3....0....2....0....0....3....0....1....3....1....0....3....1....0
..2....2....1....1....3....0....3....0....0....0....2....0....0....2....0....1
..3....1....0....0....2....1....2....0....1....3....3....3....0....0....3....0
..2....2....1....0....1....2....1....3....3....1....0....2....1....0....2....0
..1....3....2....1....3....1....3....1....0....0....0....0....3....2....1....0
..2....0....1....1....1....0....2....0....3....0....3....0....1....3....0....1
..0....3....2....3....3....1....0....3....2....3....2....1....2....1....1....2
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Column 3 of A268261.

Formula

Empirical: a(n) = 13*a(n-1) - 60*a(n-2) + 105*a(n-3) - 11*a(n-4) - 94*a(n-5) - 24*a(n-6).

Empirical g.f.: x*(13 - 126*x + 364*x^2 - 165*x^3 - 403*x^4 - 96*x^5) / ((1 - 3*x)*(1 - 4*x)*(1 - 3*x - x^2)*(1 - 3*x - 2*x^2)). - Colin Barker, Jan 11 2019