Question 1081833
Sign alternates with successive terms.
Numerator increases by 1 each term, and denominator increases by 2 for each successive term.


{{{(-1)^(n+1)}}} necessary factor for each n term.


{{{(2+(n-1))/(3+2(n-1))}}}


Put those together:
{{{((-1)^(n+1))((2+(n-1))/(3+2(n-1)))}}}