Find the closed formula for each of the following sequences by relating them to a well known sequence. Assume the first term given is \(a_1\text{.}\)
\(\displaystyle 2, 5, 10, 17, 26, \ldots\)
\(\displaystyle 0, 2, 5, 9, 14, 20, \ldots\)
\(\displaystyle 8, 12, 17, 23, 30,\ldots\)
\(\displaystyle 1, 5, 23, 119, 719,\ldots\)