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a(n) = 4 for n > 22.
Table of n, a(n) for n=1..91.
S. Eliahou and D. Hachez, On a problem of Steinhaus concerning binary sequences
Sequence in context: A242394 A030568 A017593 * A256256 A124353 A232336
Adjacent sequences: A096283 A096284 A096285 * A096287 A096288 A096289
Ralf Stephan, Aug 01 2004