### What does it mean ?

```
sage: from sage.rings.polynomial.cyclotomic import cyclotomic_coeffs
sage: cyclotomic_coeffs(30)
[1, 1, 0, -1, -1, -1, 0, 1, 1]
sage: cyclotomic_coeffs(10^5)
{0: 1, 10000: -1, 40000: 1, 30000: -1, 20000: 1}
```

I don't understand the notation. What does the last line mean ?