I was asked this question by a highly-respected political writer and couldn't come up with any convenient way to provide him with an answer. Nor does there appear to be any guidance on Google. So let me pose it to the collective:
How many unique ways are there to acquire at least 270 electoral votes without any excess?
For example, one combination would be to win California, Connecticut, the District of Columbia, Hawaii, Illinois, Maine, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, New York, Ohio, Oregon, Pennsylvania, Rhode Island, Vermont, Washington and Wisconsin. That would be equal to 272 electoral votes (not coincidentally, these are the John Kerry states plus Ohio).
Note that there are no excess electoral votes in this combination: if you remove one of the states with three electoral votes, the number falls to 269, which is below the 270-EV cut-off. So winning all of these states plus North Dakota would not qualify, since the candidate has superfluous electoral votes. On the other hand, replacing Vermont with North Dakota would make for a unique combination.
Nothing of monetary value to be provided to the winner, but I will give you a big thank you and shout-out on the front page, and your name will be immortalized in Google and possibly in a national column. I'm hoping that there's some genius out there who can solve this problem in 15 minutes.
p.s. To keep things at least somewhat simple, we probably should not worry about the split electoral votes in Maine and Nebraska.