mathematical constant
special, usually real number, that is interesting or significant in some way
Brun's constant
sum of reciprocals of twin primes
structure constants
coefficients specifying products of basis vectors as linear combinations of other basis vectors, sufficient to construct a (non-unital) algebra over a field from any vector space
Stephens' constant
mathematical constant related to the primes
pi
constant ratio of the circumference of a circle to its diameter
Hermite constant
constant relating to close packing of spheres
silver ratio
real number, second member of the sequence generalized from the golden ratio
Laplace limit
maximum eccentricity for which a power series for Kepler's equation converges
Shannon number
lower bound on the game-tree complexity for chess
reciprocal Fibonacci constant
real number, approximately 3.36, the sum of the reciprocals of the Fibonacci numbers
twelfth root of two
algebraic irrational number
prime constant
real number whose nth binary digit is 1 if n is prime and 0 if n is composite or 1
Lieb's square ice constant
mathematical constant used in combinatorics
imaginary unit
square root of negative one, used to define complex numbers
Feigenbaum constants
mathematical constants
magic constant
constant used in a magic square
omega constant
constant such that omega*e^(omega) = 1
Bernstein's constant
mathematical constant
bronze ratio
third metallic mean; three plus the square root of thirteen, divided by two
golden ratio
ratio between two quantities whose sum is at the same ratio to the larger one
universal parabolic constant
the ratio, for any parabola, of the arc length of the parabolic segment formed by the latus rectum to the focal parameter; ln(1+√2)+√2
conic constant
quantity describing conic sections
tau
ratio of the circumference of a circle to its radius
plastic ratio
unique real number solution to the equation x^3-x-1=0
Seshadri constant
invariant of an ample line bundle L at a point P on an algebraic variety
Catalan's constant
value of the Dirichlet beta function with two as the argument
Mills' constant
prime-generating mathematical constant
magic angle
the angle whose tangent is the square root of 2
Porter's constant
constant term in the average number of iterations of Euclid’s algorithm for fixed 𝑛 and averaged over all choices of relatively prime integers 𝑚<𝑛
Dottie number
mathematical constant related to the cosine function
first Feigenbaum constant
mathematical constant, approx 4.669