Why does kallisto indexing require odd-length k-mers?

Question

[ning]

I was messing around with kallisto (v0.46.2). When specifying a k-mer length of 10 (--kmer-size=10), I got this error:

Error: k needs to be an odd number

Which I thought was rather curious. Why does k need to be odd?

Answer 1

[ATpoint]

This link will answer your question, mind the paragraph Why do many tools use odd values for k:

https://bioinfologics.github.io/post/2018/09/17/k-mer-counting-part-i-introduction/