EMsieve

A titan, as defined by Samuel Yates, is anyone who has found a titanic prime. This page provides data on those that have found these primes. The data below only reflects on the primes currently on the list. (Many of the terms that are used here are explained on another page.)

User supplied image--mail editor to report abuse.

Proof-code(s):	L3839, p294, L4026, p379, L4142, L4506, L4561, L5123, CH13, p423, c98, p437, E14, p440, p453
E-mail address:	(e-mail address unpublished)
Web page:	http://sourceforge.net/projects/emsieve/
Username	EMsieve	(entry created on 3/29/2014 09:30:08 UTC)
Database id:	4141	(entry last modified on 11/8/2025 19:42:05 UTC)
Program Does *:	sieve
Active primes:	on current list: 99, rank by number 13
Total primes:	number ever on any list: 277
Production score:	for current list 55 (normalized: 7460), total 55.0925, rank by score 9
Largest prime:	516693^2097152 - 516693^1048576 + 1 ‏(‎11981518 digits) via code L4561 on 10/2/2023 00:29:30 UTC
Most recent:	30315856703599 · 3727#/2 - 8 ‏(‎1605 digits) via code E14 on 3/2/2026 02:21:51 UTC
Entrance Rank:	mean 50132.40 (minimum 7, maximum 125389)
Unprocessed:	prime submissions still untested or inprocess: 5.

Descriptive Data: (report abuse)

This code corresponds to both a simple sieve/prefactor program for the so-called Eisenstein-Mersenne Primes: 3^p +- 3^((p + 1)/2) + 1, and a special modified variant of LLR (with due credit for the original framework code to Jean Penne, and to George Woltman for GWNUM).

See http://oeis.org/A066408, A125739, and [1] for a good introduction. Some easily established properties are: p must be prime; sign is minus for p=+-1 (mod 12), plus otherwise; composites only have factors of form 6kp+1 (integer k).

After sieving, the Berrizbeitia-Iskra or the Proth test can be run; this is best implemented with FFT mod (3^3p+1) using GWNUM library. A sample implementation (a patch to the LLR program) is available from Batalov.

Also, this code is extended to an accessory GPU-assisted sieve for pre-factoring both Eisenstein-Mersenne and Gaussian-Mersenne candidates. This CUDA program is adapted from well-known mfaktc [2].

P.Berrizbeitia, B.Iskra, 2010; http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.189.311
OEIS: http://oeis.org/
http://www.mersennewiki.org/index.php/Mfaktc

Surname: EMsieve (used for alphabetizing and in codes).
Unverified primes are omitted from counts and lists until verification completed.

I administer EMsieve and I would like to