A sequence in which no term divides any other. Let 
be the set 
,
then the number of primitive subsets of 
are 2, 3, 5, 7, 13, 17, 33, 45, 73, 103, 205, 253, ... (OEIS
A051026). For example, the five primitive sequences
in 
are 
,
,
,
,
,
,
and 
.
Primitive Sequence
See also
Nondividing SetExplore with Wolfram|Alpha
References
Guy, R. K. Unsolved Problems in Number Theory, 2nd ed. New York: Springer-Verlag, p. 202, 1994.Sloane, N. J. A. Sequence A051026 in "The On-Line Encyclopedia of Integer Sequences."Referenced on Wolfram|Alpha
Primitive SequenceCite this as:
Weisstein, Eric W. "Primitive Sequence." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/PrimitiveSequence.html