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A200882 Number of 0..4 arrays x(0..n+1) of n+2 elements without any interior element greater than both neighbors. 1
95, 325, 1121, 3985, 14288, 50995, 181336, 644721, 2294193, 8166441, 29066618, 103444256, 368138471, 1310164527, 4662787112, 16594519920, 59058487061, 210183969235, 748026706926, 2662163892493, 9474416502527, 33718645047381 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A200886.

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) -10*a(n-2) +20*a(n-3) -15*a(n-4) +21*a(n-5) -7*a(n-6) +8*a(n-7) -a(n-8) +a(n-9).

Empirical g.f.: x*(95 - 150*x + 446*x^2 - 270*x^3 + 498*x^4 - 135*x^5 + 196*x^6 - 20*x^7 + 25*x^8) / (1 - 5*x + 10*x^2 - 20*x^3 + 15*x^4 - 21*x^5 + 7*x^6 - 8*x^7 + x^8 - x^9). - Colin Barker, Oct 16 2017

EXAMPLE

Some solutions for n=3

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

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

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

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

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

CROSSREFS

Sequence in context: A225931 A008875 A174157 * A217133 A055823 A116250

Adjacent sequences:  A200879 A200880 A200881 * A200883 A200884 A200885

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 23 2011

STATUS

approved

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Last modified August 13 20:26 EDT 2022. Contains 356107 sequences. (Running on oeis4.)