Multiplication error in python

[sakthi]

In the following code,
>>> l=[1,2,3,4,5]
>>> i=0
>>> for a in l:
...     p=2*a
...     t=p+i
...     i=t
...
>>> t
45

Python gives an answer as 45. But i am getting 30 when i execute
manually. Is there any different multiplication pattern in python?
Thank yu.