MathDB
Putnam 2008 A6

Source:

December 8, 2008
Putnamlogarithmsinequalitiescollege contests

Problem Statement

Prove that there exists a constant c>0 c>0 such that in every nontrivial finite group G G there exists a sequence of length at most clnG c\ln |G| with the property that each element of G G equals the product of some subsequence. (The elements of G G in the sequence are not required to be distinct. A subsequence of a sequence is obtained by selecting some of the terms, not necessarily consecutive, without reordering them; for example, 4,4,2 4,4,2 is a subesequence of 2,4,6,4,2, 2,4,6,4,2, but 2,2,4 2,2,4 is not.)