Cuemath
Cuemath: Sequences
A comprehensive guide for learning all about sequences with definitions, the types of sequences, examples of sequences, formulas for sequences, solved examples, and practice questions.
Shodor Education Foundation
Shodor Interactivate: Tortoise and Hare Race
Step through the tortoise and hare race, based on Zeno's paradox, to learn about the multiplication of fractions and about convergence of an infinite sequence of numbers.