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A200835 Number of 0..5 arrays x(0..n+1) of n+2 elements without any two consecutive increases or two consecutive decreases. 1
176, 846, 4108, 19930, 96690, 469116, 2276028, 11042700, 53576350, 259938722, 1261156090, 6118806300, 29686880836, 144033141554, 698811908924, 3390456382404, 16449625906804, 79809371351400, 387214626739458 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 5 of A200838.

LINKS

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

FORMULA

Empirical: a(n) = 6*a(n-1) -6*a(n-2) +3*a(n-3) -5*a(n-4) +3*a(n-5) -2*a(n-6) +a(n-7).

Empirical g.f.: 2*x*(88 - 105*x + 44*x^2 - 85*x^3 + 50*x^4 - 33*x^5 + 18*x^6) / (1 - 6*x + 6*x^2 - 3*x^3 + 5*x^4 - 3*x^5 + 2*x^6 - x^7). - Colin Barker, Oct 14 2017

EXAMPLE

Some solutions for n=3

..3....5....0....4....2....3....2....5....3....1....2....0....0....4....1....3

..3....4....3....1....1....5....0....1....0....1....3....5....2....5....4....4

..0....4....0....1....5....3....4....2....5....1....3....4....1....0....4....0

..0....0....2....4....0....3....2....2....4....3....1....5....1....4....4....0

..1....1....1....2....0....5....3....2....4....3....1....5....2....0....0....5

CROSSREFS

Sequence in context: A336026 A063344 A075291 * A133063 A264892 A223611

Adjacent sequences:  A200832 A200833 A200834 * A200836 A200837 A200838

KEYWORD

nonn

AUTHOR

R. H. Hardin Nov 23 2011

STATUS

approved

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Last modified September 24 22:46 EDT 2021. Contains 347651 sequences. (Running on oeis4.)