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A121894
Van der Waerden numbers: A005346(n) - 1.
2
0, 2, 8, 34, 177, 1131
OFFSET
1,2
COMMENTS
The maximum length of a string of 0's and 1's with no n-length "decimated substring" being all 0's or all 1's. A decimated substring is defined to be any subset {x_a, x_(a+p), x_(a+2p), x_(a+3p), ...} for any appropriate a, p.
Some authors prefer this version to A005346.
EXAMPLE
a(3) = 8 because 00110011 is the maximal string for n=3: appending 1 gives ......111 and appending 0 gives 0...0...0. No other starting string improves on this.
CROSSREFS
Cf. A005346.
Sequence in context: A030944 A030871 A030960 * A061370 A126328 A268558
KEYWORD
nonn,more
AUTHOR
James Dow Allen, Sep 01 2006
EXTENSIONS
Term a(6) (using A005346) from Joerg Arndt, Jun 06 2016
STATUS
approved