This paper analyses the configuration of figures wherein they follow one another, such that the former gives rise to the
later following a fixed rule. When the sequence is arithmetical, it means the variation between the first number and the next is unchanging.
The different numbers that make up the sequence are called ''terms''. And when these terms are added they form what is called a series. The writer also draws our attention to the fact that
arithmetic sequence, arithmetic
progression, linear progression and arithmetic series are synonyms of one another. Terms associated with this topic and symbols: First term (a), Common difference(d), nth term(Un), the number of terms(n). the formular thus {Un = a + (n -1)d }.