Collatz function data for 2^43112609 – 1 (#5 known megaprime) Posted on 08.12.2019 by Andrey S. Shchebetov / Андрей Щебетов We publish our first data on the Collatz function for 243112609 – 1 (#5 known megaprime) and two of its odd neighbors located at ±10. All tested numbers supported the Collatz conjecture.