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A121385
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Minimal number of three-term arithmetic progressions that a coloring of {1,...,n} can contain.
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1
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0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 31, 34, 37, 40, 43, 46
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,11
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COMMENTS
| a(9)=1 is the well known fact that the van der Waerden number for 2 colors and three-term arithmetic progressions is 9.
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EXAMPLE
| a(8)=0 because we can two color {1,...,8} by 11001100 so that there are no three-term arithmetic progressions.
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CROSSREFS
| Cf. A121386.
Sequence in context: A089197 A017874 A029016 * A029015 A000008 A001312
Adjacent sequences: A121382 A121383 A121384 * A121386 A121387 A121388
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KEYWORD
| nonn
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AUTHOR
| Steve Butler (sbutler(AT)math.ucsd.edu), Jul 26 2006
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