
What is Arithmetic Series?
sum of the terms of a sequence 
S_{n} sum of the terms of an arithmetic sequence with n terms.
S_{n} = a_{1 }+ a_{2} + a_{3} + a_{4} … + a_{n}

S_{n} =

S_{n} =
n 
Find the sum of the first 12 terms of the arithmetic series
2+5+8+11+… 
What is the sum
1+2+3+4+5++7+8+10 … +298+299