Yeah, the title is misleading because really the problem described in the blog post is to store some unknown number of ints between 1 and 10,000. The better solution than a straight bitmap of 10,000 bits is to use all 4KB and devote three bits to each slot. Then you can remember up to 7 occurrences of each integer.

There's no need for bloom filters here because you can already cover all the possibilities using a bitmap.