Mathematics for IGCSE & O level - Sequences (Section 4 - No. 30)
What is the nth term formula for the sequence 5, 9, 13, 17,...?
4n
4n + 1
4n + 5
5n + 4
توضیح
The sequence increases by 4 each time, so it will include 4n. When n=1, the term is 5, therefore, the correct formula is 4n+1.