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Mathematical constant

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A mathematical constant is a quantity, usually a real number or a complex number, that arises naturally in mathematics and does not change. Unlike physical constants, mathematical constants are defined independently of any physical measurement.

Many particular numbers have special significance in mathematics, and arise in many different contexts. For example, up to multiplication with nonzero complex numbers, there is a unique holomorphic function f with f' = f. Therefore, f(1)/f(0) is a mathematical constant, the constant e. f is also a periodic function, and the absolute value of its period is another mathematical constant, 2π.

Mathematical constants are typically elements of the field of real numbers or complex numbers. Mathematical constants that one can talk about are definable numbers (and almost always also computable).

However, there are still some mathematical constants for which only very rough estimates are known.

An alternate sorting may be found at Mathematical constant (sorted by continued fraction representation)

Table of selected mathematical constants

Abbreviations used:

R - Rational number, A - Irrational number (algebraic), T - Irrational number (transcendental)
Gen - General, NuT - Number theory, ChT - Chaos theory, Com - Combinatorics, Inf - Information theory, Ana - Mathematical analysis

Symbol Approximate Value Name Field N First Described # of Known Digits

0

0

Zero

Gen R c. 7th-5th century BC N/A

1

1

One, Unity

Gen R N/A

i

Imaginary unit

Gen, Ana A 16th century N/A

π

≈ 3.14159 26535 89793 23846 26433 83279 50288

Pi, Archimedes' constant or Ludolph's number

Gen, Ana T by c. 2000 BC 1,241,100,000,000

e

≈ 2.71828 18284 59045 23536 02874 71352 66249

Napier's constant, or Euler's number, base of Natural logarithm

Gen, Ana T 1618 50,100,000,000

2

≈ 1.41421 35623 73095 04880 16887 24209 69807

Pythagoras' constant, square root of two

Gen A by c. 800 BC 137,438,953,444

3

≈ 1.73205 08075 68877 29352 74463 41505

Theodorus' constant, square root of three

Gen A by c. 800 BC

γ

≈ 0.57721 56649 01532 86060 65120 90082 40243

Euler-Mascheroni constant

Gen, NuT

1735 108,000,000

φ

≈ 1.61803 39887 49894 84820 45868 34365 63811

Golden ratio

Gen A by 3rd century BC 3,141,000,000

β*

≈ 0.70258

Embree-Trefethen constant

NuT

δ

≈ 4.66920 16091 02990 67185 32038 20466 20161

Feigenbaum constant

ChT

1975

α

≈ 2.50290 78750 95892 82228 39028 73218 21578

Feigenbaum constant

ChT

C2

≈ 0.66016 18158 46869 57392 78121 10014 55577

Twin prime constant

NuT

5,020

M1

≈ 0.26149 72128 47642 78375 54268 38608 69585

Meissel-Mertens constant

NuT

1866
1874
8,010

B2

≈ 1.90216 05823

Brun's constant for twin prime

NuT

1919 10

B4

≈ 0.87058 83800

Brun's constant for prime quadruplets

NuT

Λ

> – 2.7 · 10-9

de Bruijn-Newman constant

NuT

1950?

K

≈ 0.91596 55941 77219 01505 46035 14932 38411 Catalan's constant

Com

201,000,000

K

≈ 0.76422 36535 89220 66

Landau-Ramanujan constant

NuT

30,010

K

≈ 1.13198 824

Viswanath's constant

NuT

8

L

= 1

Legendre's constant

NuT

μ

≈ 1.45136 92348 83381 05028 39684 85892 027

Ramanujan-Soldner constant

NuT

75,500

EB

≈ 1.60669 51524 15291 763

Erdős–Borwein constant

NuT A

β

≈ 0.28016 94990

Bernstein's constant[ ]

Ana

λ

≈ 0.30366 30029

Gauss-Kuzmin-Wirsing constant[ ]

Com

1974 385

D(1)

≈ 0.35323 63719

Hafner-Sarnak-McCurley constant[ ]

NuT

1993

λ, μ

≈ 0.62432 99885

Golomb-Dickman constant[ ]

Com NuT

1930
1964

≈ 0.62946 50204

Cahen's constant[ ]

≈ 0.66274 34193

Laplace limit[ ]

≈ 0.80939 40205

Alladi-Grinstead constant[ ]

NuT

Λ

≈ 1.09868 58055

Lengyel's constant[ ]

Com

1992

≈ 1.18656 91104

Khinchin-Lévy constant[ ]

NuT

ζ(3)

≈ 1.20205 69031 59594 28539 97381

Apéry's constant[ ]

1979 1,000,000,000

θ

≈ 1.30637 78838 63080 69046

Mills' constant[ ]

NuT

1947

≈ 1.45607 49485 82689 67139 95953 51116 54356

Backhouse's constant[ ]

≈ 1.46707 80794

Porter's constant[ ]

NuT

1975

≈ 1.53960 07178

Lieb's square ice constant[ ]

Com

1967

≈ 1.70521 11401 05367

Niven's constant[ ]

NuT

1969

K

≈ 2.58498 17596

Sierpiński's constant[ ]

≈ 2.68545 2001

Khinchin's constant[ ]

NuT

1934 7350

F

≈ 2.80777 02420

Fransén-Robinson constant[ ]

Ana

L

≈ .5

Landau's constant

Ana

1

See also

External links

 


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