TOPICS
Search

Logarithmically Convex Sequence


A logarithmically convex sequence (or log-convex sequence) is a sequence {a_n} of nonnegative real numbers for which

 a_n^2<=a_(n-1)a_(n+1),

at every applicable index. A positive sequence is logarithmically convex iff its successive quotients a_(n+1)/a_n form a nondecreasing sequence. For example, the factorial sequence {n!} is logarithmically convex.


See also

Logarithmically Concave Sequence, Logarithmically Convex Function, Partition Function Q

Explore with Wolfram|Alpha

References

Guo, H. and Zhang, Z.-R. "The Log-Convexity of the n-th Root Sequence of the Distinct Partition Function." Elec. J. Combin. 33, No. 3, P3.50, 1-22, 2026. https://doi.org/10.37236/14748.

Cite this as:

Weisstein, Eric W. "Logarithmically Convex Sequence." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/LogarithmicallyConvexSequence.html

Subject classifications