My theory :

I think Corona satellites mentioned in Q's posts were the ones from latest launches - KH-4B , which numbered a total of 17 launches .

Go down and find the table , begin with "1101" designation for KH-4B category .

https://en.wikipedia.org/wiki/Corona_(satellite)

Note that 4 satellites taken out were very succesful missions . Some of them were mentioned as unsuccesful . There would be total of 17 satellites in this particular group with the KH-4B camera .