I'm trying to determine the big O time complexity of the following data set where the first column is the input size, and the second column is the execution time in seconds. Where possible, I should determine the exponent of the dominant term and provide an estimate for the coefficient on the dominant term.
I made the following graph of the data and a log/log graph to try and figure it out. At first I thought it might have been 1/n or something along those lines but as n gets quite large, the execution time increases again instead of asymptotically approaching a value.
The log graph having such a distinct pattern leads me to believe that the answer will lie there but I'm stuck as to where to go from here. Any help would be great.