Английская Википедия:183 (number)
Шаблон:Infobox number 183 (one hundred [and] eighty-three) is the natural number following 182 and preceding 184.
In mathematics
183 is a perfect totient number, a number that is equal to the sum of its iterated totients[1]
Because <math>183 = 13^2 + 13 + 1</math>, it is the number of points in a projective plane over the finite field <math>\mathbb{Z}_{13}</math>.[2] 183 is the fourth element of a divisibility sequence <math>1,3,13,183,\dots</math> in which the <math>n</math>th number <math>a_n</math> can be computed as <math display=block>a_n=a_{n-1}^2+a_{n-1}+1=\bigl\lfloor x^{2^n}\bigr\rfloor,</math> for a transcendental number <math>x\approx 1.38509</math>.[3][4] This sequence counts the number of trees of height <math>\le n</math> in which each node can have at most two children.[3][5]
There are 183 different semiorders on four labeled elements.[6]
See also
- The year AD 183 or 183 BC
- List of highways numbered 183
- Шаблон:In title
References
Шаблон:Commons category Шаблон:Integers