6 A sequence of terms \(u _ { 1 } , u _ { 2 } , u _ { 3 } , \ldots\) is defined by
$$u _ { n } = 2 n + 5 , \quad \text { for } n \geqslant 1 .$$
- Write down the values of \(u _ { 1 } , u _ { 2 }\) and \(u _ { 3 }\).
- State what type of sequence it is.
- Given that \(\sum _ { n = 1 } ^ { N } u _ { n } = 2200\), find the value of \(N\).