A212473 Number of 0..3 arrays of length 2*n+1 with sum no more than 3*n in any length 2n subsequence (=50% duty cycle).

30, 486, 7862, 126606, 2034200, 32644314, 523487828, 8390738062, 134446993320, 2153764911576, 34495886876214, 552428007496418, 8845775486728392, 141630619844515292, 2267494906950636872, 36300174404152871822

Offset: 1

Author

R. H. Hardin May 17 2012

Keywords

• nonn

Comments

Row 2 of A212471

Examples

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

Links

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