Biology question:

Let’s assume we’re going to send a group of people off to colonize another planet, and that we’re going to send one group of people. Assume that we’ve solved all of the normal challenges to make sure the group survives, food, air, etc. What’s the minimum number of people we would have to send to ensure enough genetic diversity for the group to flourish into a full human population? In other words, how many people would have to be sent so that we don’t start getting issues such as what happens when relatives procreate.