Posted by Leonard on .
How do I use the sigma notation to express the series : 1+5+25+125+625+3125?

Math 
MathMate,
First try to make a relation/rule between the different terms:
1=5^{0}
5=5^{1}
25=5^{2}
125=5^{3}
625=5^{4}
3125=5^{5}
So you are really summing
5^{0}+5^{1}+5^{2}+5^{3}+5^{4}+5^{5}
So you would end up with:
i=5
Σ 5^{i}
i=0