A single negative number raises an error, so the two forms should be consistent.
```
In [1]: import warnings

In [2]: warnings.simplefilter('always')

In [3]: random.seed(-1)
---------------------------------------------------------------------------
OverflowError                             Traceback (most recent call last)
<ipython-input-3-c966ee99d910> in <module>()
----> 1 random.seed(-1)

/home/charris/.local/lib/python2.7/site-packages/numpy/random/mtrand.so in mtrand.RandomState.seed (numpy/random/mtrand/mtrand.c:8818)()

OverflowError: can't convert negative value to unsigned long

In [4]: random.seed([-1])

In [5]: 
```
The problem is the use of `NPY_LONG` in the array creation. Not sure what the best option is here.