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Twin prime constant
C
2
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probability theory
number theory
Number
C
2
0.660161815846869573927812110014555778432623360284733413319448423335405642304495277143760031413839867911779
Definition
C
2
:=
∏
p
≥
3
(
1
−
(
p
−
1
)
−
2
)
, where the product ranges over the odd primes
p
.
Comments
(1)
Let
π
2
(
x
)
denote the number of primes
p
≤
x
such that
p
+
2
is also a prime. The first Hardy-Littlewood conjecture implies that
π
2
(
x
)
∼
2
C
2
x
log
2
x
.
Links
[1]
OEIS: A005597
[2]
Wikipedia: First Hardy-Littlewood conjecture
Data properties
Entries are of type: real number