Definition:Ferrier's Prime/Historical Note

Historical Note on Ferrier's Prime
Ferrier's prime was discovered in $1951$ by using a manual desk calculator.

It is generally considered to have been the highest known prime at the time, having $44$ digits.

However, it was eclipsed by $180 \times \paren {2^{127} - 1} + 1$ ($79$ digits), discovered in the same month by and  of Cambridge University.

Exactly which was discovered first is debated, but 's is traditionally determined as being earlier.

Both were then well and truly superseded in $1952$, when discovered the prime nature of $2^{521} - 1$ and a number of others.

Ferrier's prime is still the largest prime number to be discovered without the help of electronic computers, and this will probably remain the case.