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A229007 Number of arrays of median of three adjacent elements of some length n+2 0..3 array, with no adjacent equal elements in the latter. 1
4, 14, 46, 130, 332, 830, 2054, 5108, 12790, 32146, 80942, 203898, 513498, 1292934, 3254868, 8193210, 20623908, 51914372, 130680214, 328953874, 828059138, 2084434524, 5247046924, 13208134738, 33248182980, 83693989466, 210678694852 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A229012.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) -5*a(n-3) +2*a(n-4) +11*a(n-5) -11*a(n-6) -2*a(n-7) +19*a(n-8) -8*a(n-9) -13*a(n-10) +28*a(n-11) -18*a(n-12) +a(n-13) +26*a(n-14) -24*a(n-15) +9*a(n-16) +15*a(n-17) -21*a(n-18) +13*a(n-19) +5*a(n-20) -12*a(n-21) +19*a(n-22) -9*a(n-23) -a(n-24) +4*a(n-25) -4*a(n-26) +2*a(n-27).

EXAMPLE

Some solutions for n=4

..2....2....2....1....3....3....1....2....2....3....2....1....2....2....2....1

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

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

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

CROSSREFS

Sequence in context: A068092 A255678 A153480 * A232060 A302238 A171851

Adjacent sequences:  A229004 A229005 A229006 * A229008 A229009 A229010

KEYWORD

nonn

AUTHOR

R. H. Hardin, Sep 10 2013

STATUS

approved

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Last modified September 29 02:49 EDT 2020. Contains 337420 sequences. (Running on oeis4.)