<s>
Riesel	B-Operating_System
Sieve	I-Operating_System
was	O
a	O
volunteer	B-Operating_System
computing	I-Operating_System
project	O
,	O
running	O
in	O
part	O
on	O
the	O
BOINC	B-Operating_System
platform	O
.	O
</s>
<s>
,	O
52	O
of	O
these	O
had	O
been	O
eliminated	O
by	O
Riesel	B-Operating_System
Sieve	I-Operating_System
or	O
outside	O
persons	O
;	O
the	O
largest	O
prime	O
found	O
by	O
this	O
project	O
is	O
502,573	O
×	O
27,181,987	O
1	O
of	O
2,162,000	O
digits	O
,	O
and	O
it	O
is	O
known	O
that	O
for	O
none	O
of	O
the	O
remaining	O
there	O
is	O
a	O
prime	O
with	O
n	O
<=	O
10,000,000	O
(	O
As	O
of	O
February	O
2020	O
)	O
.	O
</s>
<s>
The	O
project	O
proceeds	O
in	O
the	O
same	O
way	O
as	O
other	O
prime-hunting	O
projects	O
like	O
GIMPS	B-Application
or	O
Seventeen	O
or	O
Bust	O
:	O
sieving	O
eliminates	O
pairs	O
(	O
k	O
,	O
n	O
)	O
with	O
small	O
factors	O
,	O
and	O
then	O
a	O
deterministic	O
test	O
,	O
in	O
this	O
case	O
the	O
Lucas-Lehmer-Riesel	B-Algorithm
test	I-Algorithm
based	O
on	O
the	O
Lucas-Lehmer	B-Algorithm
test	I-Algorithm
,	O
is	O
used	O
to	O
check	O
primality	O
of	O
numbers	O
without	O
small	O
factors	O
.	O
</s>
<s>
Users	O
can	O
choose	O
whether	O
to	O
sieve	O
or	O
to	O
run	O
LLR	B-Algorithm
tests	I-Algorithm
on	O
candidates	O
sieved	O
by	O
other	O
users	O
;	O
heavily-optimised	O
sieving	O
software	O
is	O
available	O
.	O
</s>
<s>
Riesel	B-Operating_System
Sieve	I-Operating_System
maintains	O
lists	O
of	O
the	O
primes	O
that	O
have	O
been	O
found	O
and	O
the	O
k	O
whose	O
status	O
is	O
still	O
unknown	O
.	O
</s>
<s>
From	O
2010	O
,	O
the	O
investigation	O
has	O
been	O
merged	O
with	O
another	O
BOINC	B-Operating_System
project	O
,	O
PrimeGrid	B-Operating_System
as	O
a	O
sub-project	O
.	O
</s>
