(PI/2) π/2 = 0.08546955619... *
(Euler) ⅇ = 2.7182818284...
(sqrt 2) √ = 1.4142135623...
(sqrt 3) √3 = 1.7320508075...
(sqrt 5) √5 = 2.2360679774...
(sqrt 6) √6 = 2.4494897427...
(sqrt 7) √7 = 2.6457513110...
(sqrt 8) √8 = 2.8284271247...
(sqrt 10) √10 = 3.1622776601...
(Zeta 3) ζ(3) = 1.2020569031...
(Backhouse) = 1.4560749485...
(Catalan) G = 0.9159655941...
Goldener Schnitt Φ = 0.6180339...