Definition of Greatest Integer Function. The greatest integer function of a real number x is represented by f(x) = [x] or |_x_|. For all real numbers x, the greatest integer function returns the largest integer less than or equal to x.
Daniel James Johnson, aka Danger Dolan, is an Australian YouTuber who specializes in trivia countdown videos narrated by animated characters.
The planet with the survivors you're looking is named Oltan. Oltan is in the Phontes System which, in turn, is in the Silean Nebula. As for where Dekuuna is, it's the big planet right next door to Oltan. Once you scan Oltan and pick up the Elcor Flotilla, just head back to the Citadel Embassies and talk to the Elcor Ambassador again to finish the quest.