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Arima Yoriyuki
Japanese mathematician / From Wikipedia, the free encyclopedia
Arima Yoriyuki (有馬 頼徸, December 31, 1714 – December 16, 1783) was a Japanese mathematician of the Edo period. He was the lord of Kurume Domain.
In this Japanese name, the surname is Arima.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/0/0b/Arima_Yoriyuki.jpg/640px-Arima_Yoriyuki.jpg)
He approximated the value of and its square,
. In 1766, he found the following rational approximation of
, correct to 29 digits:[1][2]