Example:
1, 
3, 
9, 
5, 
7, 
(d= 2) 
1(a), 
1+2(d), 
1+2x2(d), 
1+3x2, 
1+4x2, 

a= the first term of the arithmetic progression, the starting point.
d= the common difference between the terms.
n= the number of terms in the arithmetic progression.
an= the nth value.
Example: Given an arithmetic progression with the initial term 5 and the common difference 7, what is the 10th term?
an = 5 + (101)7
an = 5 + (9)7
an = 5 + 63
an = 68
Example:
2 
6 
18 
54 
2(a) 
2x3(r) 
2x3*2 
2x3*3 
a= the first term of the geometric progression, the starting point.
r= the common ratio between the terms.
n= the number of terms in the geometric progression.
an= the nth value.
Fn= Phin – (Phi)n
√5
Or
Fn= 1.6180339..n –(1.16180339)n 2.236067977