many countries accept foreigner to open business.
USA is one of the best country to open your business, you dont even need to be present to open your business firm in usa if you use this service.
https://www.paxux.com/In one week they will form your business firm and your get all your papers. If your business its about ICO just exclude us citizen to participate in your ico.
Other alternative , you can open your business in panama, panama is open for all foreigners. I saw many icos like monsterbyte from panama, blockchainoid is from panama.
The best country is russia, major ico are from russia. playkey,cartaxi