[QUOTE=3.14159;222123]I actually did find it. Stop making false assumptions:
[URL="http://en.wikipedia.org/wiki/Coin_problem"]Here it is.[/URL]

[URL="http://mathworld.wolfram.com/CoinProblem.html"]A better source.[/URL][/QUOTE]

Then why did you have to ask if it were proven?

[QUOTE]Then why did you have to ask if it were proven?[/QUOTE]

I previously didn't know what it was. I merely followed your tip + CRG's "searchbait".