On November 14, 2017 our data on number of steps in Collatz sequence for Mersenne primes with the provisional index from 46th to 49th were included in OEIS as a comment to A181777. Prior to this A181777 contained information up to the 45th Mersenne prime only.

Previously, on September 14, 2017, the data on required number of steps to reach 1 for the 43rd, 44th and 45th Mersenne primes were already included into A181777.

Below is a table with our data for all known Mersenne primes starting from the 43rd.

Mp                             # of steps to 1
43(M30402457)        409093991
44(M32582657)        438465334
45(M37156667)        499902411
46(M42643801)        573966881
47(M43112609)        580260946
48(M57885161)        779044992
49(M74207281)        998401306

As far as we know, full Collatz conjecture statistics for large Mersenne primes has never been published before and none of Mersenne primes above the 47th one (M43112609) has ever been tested for Collatz conjecture confirmation.

We continue to process our results and plan to present most important of them in the future.