Collatz function data for 2^74207281 – 1 (#3 known megaprime) Posted on 14.12.2019 by Andrey S. Shchebetov / Андрей Щебетов We publish our first data on the Collatz function for 274207281 – 1 (#3 known megaprime) and two of its odd neighbors located at ±6. All tested numbers supported the Collatz conjecture.