A212474 Number of 0..3 arrays of length 2*n+2 with sum no more than 3*n in any length 2n subsequence (=50% duty cycle).

85, 1597, 27024, 445780, 7274268, 118029501, 1908601444, 30794657082, 496095308012, 7983014938756, 128351434757356, 2062286003105664, 33118464621596452, 531627920798750598, 8530886270887938488

Offset

1,1

Comments

Row 3 of A212471.

Links

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

Example

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

Crossrefs

Cf. A212471.

Sequence in context: A206377 A351105 A008360 * A020310 A163692 A221339

Adjacent sequences: A212471 A212472 A212473 * A212475 A212476 A212477

Keyword

nonn

Author

R. H. Hardin, May 17 2012

Status

approved