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A229008
Number of arrays of median of three adjacent elements of some length n+2 0..4 array, with no adjacent equal elements in the latter.
1
5, 23, 101, 359, 1145, 3527, 10735, 32907, 101635, 315579, 982305, 3059025, 9524031, 29640801, 92224095, 286910991, 892560177, 2776725201, 8638459639, 26874806287, 83609764417, 260117322353, 809247413805, 2517636208515, 7832571212121
OFFSET
1,1
COMMENTS
Column 4 of A229012.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) -a(n-2) -10*a(n-3) +7*a(n-4) +35*a(n-5) -47*a(n-6) -9*a(n-7) +106*a(n-8) -43*a(n-9) -123*a(n-10) +248*a(n-11) -30*a(n-12) -255*a(n-13) +370*a(n-14) +13*a(n-15) -396*a(n-16) +484*a(n-17) +88*a(n-18) -609*a(n-19) +715*a(n-20) -62*a(n-21) -603*a(n-22) +830*a(n-23) -305*a(n-24) -450*a(n-25) +825*a(n-26) -580*a(n-27) -91*a(n-28) +586*a(n-29) -678*a(n-30) +304*a(n-31) +130*a(n-32) -423*a(n-33) +364*a(n-34) -103*a(n-35) -83*a(n-36) +176*a(n-37) -111*a(n-38) +25*a(n-39) +37*a(n-40) -32*a(n-41) +17*a(n-42) -2*a(n-43) -4*a(n-44) +2*a(n-45) -a(n-46).
EXAMPLE
Some solutions for n=4
..1....2....3....2....2....3....2....1....0....1....0....2....3....1....0....3
..2....2....3....3....3....0....0....1....1....4....2....1....1....3....4....2
..1....0....3....1....1....2....4....2....1....2....1....1....4....2....2....1
..3....1....1....4....3....1....3....4....1....2....3....0....0....2....2....0
CROSSREFS
Sequence in context: A077277 A073682 A034958 * A274322 A085350 A113443
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 10 2013
STATUS
approved