Answer:
The answer is 0.
Step-by-step explanation:
Let's call the answer a.
We want to find a(2004)
That's an even term. We look at the even terms:
2 Â 2002
 4  2000
6 Â 1998
8 Â 1996
10 Â 1994
12 Â 1992
Â
We see that the pattern for the even terms is Â
"if you add n and a(n), the sum is always 2004."
That is n + a(n) = 2004, or,
      a(n) = 2004-n when n is even
So when n = 2004, a(2004) = 2004-2004 = 0
Answer: 0