### Home > PC > Chapter 2 > Lesson 2.3.1 > Problem2-72

2-72.

Express the given series using sigma notation, then evaluate the sums with your program or by hand.

1. $4+8+12+16+20$

All of the numbers in the series are multiples of $4$.

1. $1+2+4+8+16+32$

The numbers in this series are all powers of $2$.
It is easier to start with an index of $k=0$ instead of $k=1$.

1. $2+4+6+8\ +\ ...\ +\ 200$

All of the numbers in the series are multiples of $2$.