Only three federal prisoners were executed between 1964 and May of 2020. One of them was Timothy McVeigh, which goes to show you don't fuck with the IRS.
Since then, over the last 6 months, the Justice Department has executed 8 federal prisoners, and 5 more are scheduled for elimination. So it's looking like 13 federal prisoners may be executed during Trump's presidency. Maybe even more, as Barr indicated in an interview with the Associated press that he plans to schedule more executions before the leaves the Justice Department. See https://www.bbc.com/news/world-us-canada-55236260
This quote from the article is interesting:
"The first set of executions this summer - during a wave of anti-racism protests and demonstrations - were all of white men. Now, four of the five prisoners scheduled to be put to death are African American."
The article notes that "more than 160 individuals sentenced to death in the US since 1973 have later been exonerated."