Jacob does not speak or let anyone touch him, including his father. He sees the world in numbers, and seems to have a special ability to predict future events and make sure that people who are destined to meet, do so. His obsession with numbers - the Amelia Sequence in particular - turns out to be the way he communicates with others, mainly his father. 318 is the first part of The Amelia Sequence, also found by Arthur Teller. Though he has received no formal training in complex mathematics, he has discovered the Fibonacci sequence on his own simply through observation and his unique perception of the world around him.