Summation and Product Notation

More specifically,

Sort of like a loop

for (let n = start; n <= end; n++) {
    yield a[n]
}

1. Multiplying by a constant

2. Adding and subtracting two sums

3. Changing the bounds of the index of summation

4. Breaking a sum apart

A recurrence relation defines a sequence of values by giving one or more initial terms, together with an equation expressing each subsequent term in terms of earlier ones.

where and