Looking on the internet deeply has found these results:

Sudan is the most popular phrase on the web.

Sudanian 1125,000 results on the web	Sudan 1258,000,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	Someone also spoke of sanctions against Sudan. 'Follow the giant bodyguard Sudan deftly avoiding the photographers, I think you would intimidate most of the men in Sudan. And I will bring peace to Sudan. A commercial airliner flying over the Sudan. We are also considering using the Port of Sudan. Sudan has a strategic importance to this country. Forces led by Gadet attacked and captured Kaka, Upper Nile State from the Sudan People's Liberation Army (SPLA) in late March 2014.

Sudanian

1125,000 results on the web

Sudan

1258,000,000 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

Someone also spoke of sanctions against Sudan.
'Follow the giant bodyguard Sudan deftly avoiding the photographers,
I think you would intimidate most of the men in Sudan.
And I will bring peace to Sudan.
A commercial airliner flying over the Sudan.
We are also considering using the Port of Sudan.
Sudan has a strategic importance to this country.
Forces led by Gadet attacked and captured Kaka, Upper Nile State from the Sudan People's Liberation Army (SPLA) in late March 2014.