A factor is a positive integer that divides evenly into a given number. For example, the factors of 8 are 1, 2, 4, and 8.

The factors of a number are all positive integers that divide evenly into the number. The factors of 16 are 1, 2, 4, 8, 16.

The equation for this sequence is:

a_n = a_n-1 + 2(n - 1)

where n is the term's order in the sequence, a_n is the value of the term, and a_n-1 is the value of the term before a_n. This makes the next number:

a₆ = a₅ + 2(6 - 1)
a₆ = 21 + 2(5)
a₆ = 31

If 53% of the town's 42,000 voters cast ballots the number of votes cast is:

(\( \frac{53}{100} \)) x 42,000 = \( \frac{2,226,000}{100} \) = 22,260

The mayor got 65% of the votes cast which is:

(\( \frac{65}{100} \)) x 22,260 = \( \frac{1,446,900}{100} \) = 14,469 votes.

The factors of 40 are [1, 2, 4, 5, 8, 10, 20, 40] and the factors of 24 are [1, 2, 3, 4, 6, 8, 12, 24]. They share 4 factors [1, 2, 4, 8] making 8 the greatest factor 40 and 24 have in common.