“I am” in Greek Septuagint translation of Exodus 3:14 vs. John 8:58 – how do they compare?

Exodus 3:14 YLT And God saith unto Moses, ‘I AM THAT WHICH I AM;’ He saith also, ‘Thus dost thou say to the sons of Israel, I AM hath sent me unto you. How does the translation of the Greek Septuagint of the "I am" in Exodus 3:…