And I realised that Euler had found two formulae for Pi which can be used to calculate any hex digit of Pi.
I wrote this up in a paper:
"In 1779 Euler discovered two formulas for π which can be used to calculate
any binary digit of π without calculating the previous digits. Up until now
it was believed that the first formula with the correct properties (known as
a BBP-type formula) for this calculation was published by Bailey, Borwein
and Plouffe in 1997."
In particular I read this one: http://eulerarchive.maa.org/hedi/HEDI-2009-02.pdf
And I realised that Euler had found two formulae for Pi which can be used to calculate any hex digit of Pi.
I wrote this up in a paper:
"In 1779 Euler discovered two formulas for π which can be used to calculate any binary digit of π without calculating the previous digits. Up until now it was believed that the first formula with the correct properties (known as a BBP-type formula) for this calculation was published by Bailey, Borwein and Plouffe in 1997."
https://scholarlycommons.pacific.edu/euleriana/vol3/iss1/3/