If there were no limits to increasing the atomic number, the element that would follow helium in the periodic table would be ununoctium (Uuo) or element 118.
Ununoctium is a synthetic element that was first synthesized in 2002 by a team of Russian and American scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. It is an extremely heavy and highly unstable element, belonging to the noble gases group.
However, it's important to note that this information is based on the periodic table Since then, there may have been new elements discovered or synthesized. Scientists continue to explore and create new elements beyond the currently known ones.