A254691 Number of length n+4 0..1 arrays with every five consecutive terms having the maximum of some two terms equal to the minimum of the remaining three terms.

22, 34, 54, 86, 136, 212, 334, 532, 852, 1367, 2193, 3522, 5669, 9143, 14763, 23854, 38564, 62381, 100966, 163491, 264822, 429064, 695313, 1126988, 1826949, 2962017, 4802762, 7788052, 12629762, 20482614, 33219658, 53879144, 87389439, 141744960

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) - a(n-2) + a(n-3) - a(n-4) + 3*a(n-5) - 3*a(n-6) - 2*a(n-8) + a(n-9) - 3*a(n-10) + a(n-11) + a(n-13) + a(n-15).

Empirical g.f.: x*(22 - 10*x + 8*x^2 - 10*x^3 + 6*x^4 - 60*x^5 - 22*x^6 - 34*x^7 - 6*x^8 - 31*x^9 + 25*x^10 + 15*x^11 + 23*x^12 + 11*x^13 + 16*x^14) / ((1 - x + x^2)*(1 - x^2 - x^3)*(1 - x - x^3 - 2*x^5 + x^8 + x^10)). - Colin Barker, Dec 17 2018

Example

Some solutions for n=10:
..0....1....0....0....0....0....1....1....0....0....1....0....1....0....1....0
..0....0....0....1....0....0....0....0....1....0....0....1....0....0....0....0
..1....1....0....0....0....1....0....0....1....0....0....0....0....0....0....1
..0....1....0....0....0....0....0....0....0....1....1....0....1....1....1....1
..0....1....0....0....0....0....0....0....0....0....0....1....0....0....0....0
..0....1....0....0....0....0....0....1....0....0....0....0....0....1....0....0
..0....1....1....0....0....1....0....1....0....0....0....0....1....0....0....0
..0....1....0....0....0....0....0....0....1....0....1....0....0....0....0....1
..0....1....0....1....1....0....1....0....0....0....1....0....0....1....0....0
..0....1....0....0....0....0....0....0....0....0....0....1....0....0....0....1
..0....1....0....0....1....0....0....1....1....0....0....0....0....0....0....0
..1....1....1....1....0....1....1....1....0....0....0....0....1....0....0....0
..1....1....0....0....0....0....0....0....0....1....1....0....1....1....1....1
..0....0....0....1....0....0....1....0....0....1....1....0....0....0....1....0

Crossrefs

Column 1 of A254698.

Sequence in context: A125526 A181177 A124317 * A159518 A245365 A100039

Adjacent sequences: A254688 A254689 A254690 * A254692 A254693 A254694

Keyword

nonn

Author

R. H. Hardin, Feb 05 2015

Status

approved