A242079 a(1)=1. a(n)=smallest integer greater than 2*a(n-1) such that the Nim sequence of the first n terms is ternary, periodic and not equal to the Nim sequence of the first n-1 terms.

1, 4, 12, 28, 73, 163, 343, 867, 1915, 4011, 8203

Offset

1,2

Comments

In the sequence definition, "Nim sequence of a set" means "Nim sequence of the subtraction game with that subtraction set."

This sequence is not known to be infinite.

If this sequence is infinite, then its Nim sequence is ternary and aperiodic.

References

E. R. Berlekamp, J. H. Conway and R. K. Guy, ``Winning Ways'', pp. 83-86

Links

Table of n, a(n) for n=1..11.

N. Fox, Aperiodic Subtraction Games, Talk given at the Rutgers Experimental Mathematics Seminar, May 01 2014.

Crossrefs

Sequence in context: A173380 A002932 A337441 * A334322 A302763 A121312

Adjacent sequences: A242076 A242077 A242078 * A242080 A242081 A242082

Keyword

nonn

Author

Nathan Fox, May 03 2014

Status

approved