A207095 Number of 0..3 arrays x(0..n-1) of n elements with each no smaller than the sum of its two previous neighbors modulo 4.

4, 10, 26, 68, 176, 458, 1193, 3103, 8069, 20982, 54556, 141854, 368847, 959072, 2493770, 6484280, 16860367, 43840173, 113992823, 296403114, 770704718, 2003979505, 5210729566, 13548892363, 35229708616, 91603972925, 238187830252

Offset: 1

Author

R. H. Hardin Feb 15 2012

Keywords

• nonn

Comments

Column 3 of A207100

Examples

			Some solutions for n=5
..0....2....2....0....2....0....1....2....0....1....2....0....1....0....1....3
..2....3....2....0....3....1....1....3....1....2....2....2....1....0....2....3
..3....1....3....0....2....3....2....3....2....3....2....3....3....3....3....2
..2....3....1....1....3....2....3....3....3....2....3....2....2....3....2....3
..3....2....2....1....1....3....2....2....1....2....3....1....2....3....3....3
		

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -a(n-2) +a(n-3) -3*a(n-4) +a(n-6) -2*a(n-9) +2*a(n-12) +a(n-13) -a(n-16)