Now here is an interesting one...
The Northrop YB-49 was the turbojet powered version of the YB-35 piston engine powered flying wing bomber prototype
It first flew in 1947 and boasted eight turbojet engines. Of the thee prototypes built two were lost due to accident and the third was scrapped after cancellation of the contract.
A lot of the original test data from the YB-49 was used decades later in the development of the B2 Stealth Bomber.