A quick and dirty way of getting your array filled from web.config would be:
In web.config:
<appSettings>
<add key="IntegerArrayMembers" value="45,54" />
</appSettings
Then in your code:
int[] integerArray = new List<string>(ConfigurationManager.AppSettings["IntegerArrayMembers"].Split(',')).ConvertAll<int>(s => int.Parse(s)).ToArray();
So you could then call your method with:
method(integerArray[0], integerArray[1]);