In a certain sequence the term an is given by the formula:
an=an−1+2n−1 for all integer n>1. If a7=49, what is a1?	Choose the most appropriate option.
A) −1	B) 0	C) 1	D) 2	E) 3
an=an−1+2n−1an=an−1+2n−1....   as we can see that each subsequent term is 2n-1 greater than previous..   so we can straightway find a7a7=(2*1-1)+(2*2-1)+(2*3-1)+(2*4-1)+(2*5-1)+(2*6-1)+(2*7-1)+a1a1=3+5+7+9+11+13+a1a1   a7a7=49=48+a1a1..   or a1a1=1   ans 1
<result>C</result>
In a certain sequence the term an is given by the formula:
an=an−1+2n−1 for all integer n>1. If a7=49, what is a1?