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A256814 Number of length n+6 0..1 arrays with at most two downsteps in every 6 consecutive neighbor pairs. 1
120, 229, 442, 856, 1656, 3204, 6192, 11955, 23088, 44617, 86226, 166620, 321960, 622104, 1202016, 2322567, 4487848, 8671757, 16756074, 32377024, 62560664, 120883084, 233577104, 451331323, 872088416, 1685098737, 3256043394 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 6 of A256816.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) -a(n-2) +2*a(n-3) -a(n-4) +3*a(n-6) -2*a(n-7) -6*a(n-9) +4*a(n-10).

Empirical g.f.: x*(120 - 11*x + 104*x^2 - 39*x^3 + 48*x^4 + 93*x^5 - 190*x^6 - 128*x^7 - 250*x^8 + 252*x^9) / ((1 - x)*(1 - x - 2*x^3 - x^4 - x^5 - 4*x^6 - 2*x^7 - 2*x^8 + 4*x^9)). - Colin Barker, Jan 24 2018

EXAMPLE

Some solutions for n=4:

..1....1....0....0....1....1....1....0....1....0....1....1....0....0....0....0

..1....0....1....0....0....1....0....1....0....0....0....0....0....1....0....0

..1....0....0....1....0....1....0....1....1....0....0....0....0....0....1....1

..0....0....1....1....1....1....0....0....1....1....0....1....1....0....1....0

..1....0....1....1....0....0....0....0....0....0....1....0....1....0....0....1

..1....1....1....1....1....1....0....0....1....0....0....0....0....0....1....0

..1....0....1....0....1....1....0....1....1....0....0....1....0....1....0....0

..1....1....0....1....0....1....0....0....1....1....1....1....1....0....0....0

..0....0....0....0....0....0....0....1....0....0....0....1....1....0....1....1

..1....0....1....1....0....0....0....0....1....0....0....1....1....1....1....0

CROSSREFS

Cf. A256816.

Sequence in context: A098565 A084142 A349745 * A232743 A146950 A028976

Adjacent sequences:  A256811 A256812 A256813 * A256815 A256816 A256817

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 10 2015

STATUS

approved

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Last modified May 28 15:04 EDT 2022. Contains 354115 sequences. (Running on oeis4.)