Something went horribly wrong with this post -- so I will repost.

Gennaro,

The reason relates to the structure of the Wolfram Language. WL is list-based (similar to LISP or SCHEME). The power of these languages is in handling operations over lists. Furthermore, these languages do not distinguish between program and data -- you can combine them -- for example you can have a list of programs or a list with both data (such as equations) and programs (functions).

You can program WL sequentially (using DO and FOR) but you lose much of the power of the language and operations are slower because EL is optimized for lists. It is best to replace FOR with MAP or its related functions. You will also find that the programs become simpler if you avoid looping constructs and move to list-based constructs.

I hope this helps.

Regards

Gennaro, a side note. Stephen Wolfram mentions in his book "An Elementary Introduction To The Wolfram Language" on page 237 that the For command is almost always a bad idea, and can almost always be replaced by much cleaner code using constructs such as Table.

Sorry, I don't know the reason. I was alerting you to Stephen Wolfram's statement since you were using a For command to solve your problem.

Regards

Gennaro, try this: Table[FourierCoefficient[Sin[t], t, i], {i, -10, 10}] Regards,