
6-2 Discrete Mathematical Structures
1. 1, 1, 0, 0, 1, 1 is a finite sequence.
2. 1, 3, 5, 7, 9, 10, 12, 14 is a finite sequence.
3. 1,
,
,
1
,… is an infinite sequence.
4. 1, 3, 5, 7,… is an infinite sequence.
5. The sequence
,
,
,… can also be written as a
n
= 2
-n
, n ≥ 1
6. The sequence 1, -1, 1, -1,… can be written as a
n
= (-1)
n+1
,
n ≥ 1
7. The sequence 1, -1, 1, -1,… can be written as b
n
= (-1)
n
, n = 0, 1, 2…
Note 6.1
1. In a sequence, the elements may all be different or some of them may be repeated.
2. Some authors write the sequence starting with n = 0 instead of n = 1.
6.2.1 Recurrence Relation
Consider the sequence ...