Question

The nth term of a sequence is n2 + 4
Alex says
"The n th term of the sequence is always a prime number when n is an odd number.”
Alex is wrong.
Give an example to show that Alex is wrong.

Answer 1

1 is an odd number so let’s put 1 into n, (1)2+4 which equals 2+4 which is 6, 6 is not a prime number as it can has factors such as 2&3 not just 1&6.