you can stop mining from now)
coin2x.com will double your dogecoins after 48 hours. try it)
Can you explain why you are able to double the coins?
I think I now the answer:

You know what's really funny thing ? That it actually doubles the invested coins, I tried it and they did pay out. You can even go on their website and check the addresses on the blockchain. Each and every address that made a deposit REALLY got double the coins after 48 hours... And no I am not trolling.
Yes I know it sounds to good to be true but what they are doing is this:
They "take" your coins and go with them on the market, and they do the trades instead of you and every profit that they make out of your "money" it stays with them, they only pay out double that you invested and then keep the rest of earned money for them.
Wouldn't you like to have for example 2 million DOGE to play on the market with ? It's just they know how to make the best out of it and earn fast.