How to remove numbers that only show up once in a list of recurring numbers

I have a list of numbers that goes something like this but much longer:

1,1,1,1,2,3,3,3,3,4,5,5,5,5,6,7,7,7,7,7,7,8,....,53,54,54,54,54,54

I tried to use histcount to remove all the numbers that show up only once, but it did not work (I pasted the code below). The main reason I am having an issue with this is because the intervals of same numbers are different, for example 1 shows four times while 7 shows up six times. I've also attempted indexing but I could not figure out how to properly index something like this without returning wierd values in the index vector.

Answer 1

[TADA]

x = [1,1,1,1,2,3,3,3,3,4,5,5,5,5,6,7,7,7,7,7,7,8,53,54,54,54,54,54];
numbers = 1:max(x);
numx = accumarray(x(:), 1);
atLeast2 = numbers(numx >= 2);
x2 = x(ismember(x,atLeast2))