Question

What is the sum of the first 30 terms in a(n)=4n+1

Answer 1

Hello,

$\sum _{i=1} ^{30}(a_i)=\sum _{i=1} ^{30}(4*i+1)\\ =4*\sum _{i=1} ^{30}(i) +\sum _{i=1} ^{30}(1)\\ =4* \dfrac{31*30}{2} + 30 =1860+30=1890$