A212723 Number of 0..2 arrays of length n+3 with sum less than 4 in any length 4 subsequence (=less than 50% duty cycle)

31, 67, 148, 322, 677, 1439, 3086, 6625, 14161, 30244, 64669, 138374, 295991, 632942, 1353515, 2894804, 6191317, 13241220, 28318162, 60563023, 129525173, 277012820, 592439104, 1267031754, 2709766972, 5795308821, 12394271806, 26507289874

Offset

1,1

Comments

Column 2 of A212729

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-2) +a(n-3) +5*a(n-4) +a(n-5) -2*a(n-6) -3*a(n-7) -6*a(n-8) -2*a(n-9) +a(n-10) +3*a(n-11) +4*a(n-12) -a(n-15) -a(n-16)

Example

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

Crossrefs

Sequence in context: A044514 A142110 A110831 * A193573 A086042 A086051

Adjacent sequences: A212720 A212721 A212722 * A212724 A212725 A212726

Keyword

nonn

Author

R. H. Hardin May 25 2012

Status

approved