A121894 Van der Waerden numbers: A005346(n) - 1.

0, 2, 8, 34, 177, 1131

Offset: 1

Author

James Dow Allen, Sep 01 2006

Keywords

• nonn
• more

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.

Examples

			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.

Extensions

Term a(6) (using A005346) from Joerg Arndt, Jun 06 2016