A very crude rule of thumb might be to divide the square root of the similarity-patch sizes into n, so that the effective sample sizes are 58 and 107 for these patches, respectively. Again, statistical significance falls with lower effective sample size.
A rough estimate is to divide the square root of the similarity-patch sizes by n, resulting in effective sample sizes of 58 and 107 for the patches.  This approach reduces statistical significance with smaller sample sizes.