Math Medics
S.o.s. Math: Sequences: Basic Definitions
This lesson thoroughly discusses sequences in mathematics. Includes information about increasing, decreasing, monotonic, and bounded sequences.
Other
Interactive Real Analysis: Sequence of Numbers
This is a short lesson from the Seton Hall University explaining increasing and decreasing sequences.
Wolfram Research
Wolfram Math World: Decreasing Sequence.
This site provides a brief overview of a decreasing sequence. Content also includes a full definition of a sequence.