For most regular coins the premine amount/blockreward structure can bee seen through github/src/main.cpp and searching for the word "nsubsidy".
For example:
https://github.com/PIVX-Project/PIVX/blob/master/src/main.cpp#L1617nHeight is the block number and subsidy is the blockreward.
So if you see this:
if (nHeight == 0) {
nSubsidy = 60001 * COIN;
That means that there's a 60001 premine at block 1 (0).
@bathrobehero: Thanks. Since you said most, would you like to quote an example of an outlier as well? Also, what about other parameters? Are they also usually in github/src/main.cpp?