Love this Arithmetic and Geometric Sequence, Sum, Nth Term, Cheat Sheet/Foldable! This is a comprehensive guide to the Arithmetic and Geometric Series. Summation notation is included along with common difference, common ratio, nth term, sum of a finite sequence and sum of an infinite sequence.
An infinite series is a sum of an infinite number of terms. Of course, the indexing can start at any integer, but by the most common starting indices are 0 0 and 1 1 . Regarding the second summation notation, of course there is no "infinity-th" term, as infinity is an not an integer; however, the notation is a convenient way for us to say that we take the summation over all natural numbers. ... See more at expii.