It should be obvious that when searching for squares we want to search above sqrt(1020304050607080900) ~ 101010101

and below sqrt(1929394959697989990) ~ 1389026623. My code starts at 101010100 and check's 101010100 + 30, 101010100 + 70, if neither if correct than + 100 and check again (Incorporates both our point 1 and 2)