A249702 Number of length n+3 0..3 arrays with every four consecutive terms having the maximum of some two terms equal to the minimum of the remaining two terms.

100, 208, 440, 896, 1724, 3440, 7056, 14544, 29620, 60416, 124156, 256448, 529304, 1091952, 2255920, 4669824, 9673196, 20037568, 41516752, 86070656, 178513920, 370298992, 768179120, 1593817584, 3307416676, 6864100336, 14246134420

Offset: 1

Author

R. H. Hardin, Nov 04 2014

Keywords

• nonn

Comments

Column 3 of A249707

Examples

			Some solutions for n=6
..1....1....3....1....0....1....1....1....2....2....1....1....2....0....2....0
..2....2....2....2....1....1....0....1....2....1....0....1....2....3....2....2
..2....2....0....2....2....1....2....2....3....2....1....1....2....1....3....3
..3....2....2....2....1....0....1....1....1....2....1....1....2....1....2....2
..2....1....2....3....1....2....1....1....2....2....1....3....2....0....2....0
..2....3....3....0....0....1....1....1....2....2....1....0....2....1....2....2
..2....2....1....2....1....1....1....1....2....0....1....1....1....1....3....2
..3....2....2....2....2....1....0....0....3....3....0....1....3....1....2....3
..0....1....2....2....1....3....3....3....1....2....3....3....2....0....2....2
		

Links

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

Formula

Empirical: a(n) = 2*a(n-1) -a(n-2) +12*a(n-4) -10*a(n-5) -41*a(n-8) -6*a(n-9) -2*a(n-10) +2*a(n-11) +44*a(n-12) +36*a(n-13) +16*a(n-14) -24*a(n-16) -24*a(n-17)