A sequence is defined recursively. Write the first five terms.
\[
a_{1}=-1 ; \quad a_{n}=n+a_{n-1}
\]

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Answer

Final Answer: The first five terms of the sequence are \(\boxed{-1, 1, 4, 8, 13}\)

Steps

Step 1 ：The sequence is defined recursively with the first term given as \(-1\) and the nth term defined as the sum of n and the previous term.

Step 2 ：To find the first five terms, we calculate each term based on the previous term.

Step 3 ：Using the given formula, the first five terms of the sequence are calculated as follows: \[-1, 1, 4, 8, 13\]

Step 4 ：Final Answer: The first five terms of the sequence are \(\boxed{-1, 1, 4, 8, 13}\)