# Summing primes, cannot convert to int

What can I do so that the following code works:

```
sage: var('k')
sage: sum(nth_prime(k),k,1,10)
ValueError: cannot convert k to int
```

Thanks in advance!

Summing primes, cannot convert to int

What can I do so that the following code works:

```
sage: var('k')
sage: sum(nth_prime(k),k,1,10)
ValueError: cannot convert k to int
```

Thanks in advance!

2

Don't involve symbolic variables.

Try this instead:

```
sage: sum(nth_prime(k) for k in (1 .. 10))
129
```

Asked: **
2015-06-19 08:33:10 -0500
**

Seen: **400 times**

Last updated: **Jun 19 '15**

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The reason this

doesn'twork while`sum(x^2,x,1,10)`

does is because`nth_prime`

isn't a symbolic expression, it's just a random Sage function.`nth_prime(x)`

already fails all by itself.