We know that a(n)=4n+1 To find the sum of the first n<span> terms of an arithmetic series use the formula </span><span><span>Sn</span>=<span>n(<span>a1</span> + <span>an</span>)/2 </span></span>a1--------------> is the first term an--------------> is the last term n--------------- > <span>is the number of terms </span>we have that a1------------> 4*(1)+1=5 a30----------> 4*(30)+1=121 n------------- > 30 S30=30*(5 + 121)/2=1890
