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A121386 Number of different two-colorings of {1,...,n} that minimize the number of monochromatic three-term arithmetic progressions that such a coloring can contain. 1

%I

%S 2,4,6,10,14,20,16,6,36,8,44,10,8,30,16,8,12,2,12,28,64,110,96,134,56,

%T 44,16,2,16,74,116,188,200,180

%N Number of different two-colorings of {1,...,n} that minimize the number of monochromatic three-term arithmetic progressions that such a coloring can contain.

%C The unique (up to switching colors) sequences for n=18 and n=28 are 001001111000011011 and 0001100011111100000011100111 respectively.

%e a(3)=6 because all non-monochromatic colorings are such an example

%Y Cf. A005346, A121385.

%K nonn

%O 1,1

%A _Steve Butler_, Jul 26 2006

%E Definition corrected by _Rob Pratt_, Jun 11 2014

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Last modified May 19 18:35 EDT 2022. Contains 353847 sequences. (Running on oeis4.)