Английская Википедия:75 (number): различия между версиями

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(Новая страница: «{{Английская Википедия/Панель перехода}} {{Infobox number |number=75 |divisor=1, 3, 5, 15, 25, 75 }} '''75''' ('''seventy-five''') is the natural number following 74 and preceding 76. __TOC__ ==In mathematics== '''75''' is a self number because there is no integer that added up to its own digits adds up to 75.<ref>{{Cite OEIS|A003052}}</ref> It is the sum of the first five pentagona...»)
 
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Текущая версия от 12:32, 26 декабря 2023

Шаблон:Infobox number 75 (seventy-five) is the natural number following 74 and preceding 76.

In mathematics

75 is a self number because there is no integer that added up to its own digits adds up to 75.[1] It is the sum of the first five pentagonal numbers, and therefore a pentagonal pyramidal number, as well as a nonagonal number.[2][3]

It is also the fourth ordered Bell number, and a Keith number, because it recurs in a Fibonacci-like sequence started from its base 10 digits: 7, 5, 12, 17, 29, 46, 75...[4]

75 is the count of the number of weak orderings on a set of four items.[5]

Excluding the infinite sets, there are 75 uniform polyhedra in the third dimension, which incorporate star polyhedra as well. Inclusive of 7 families of prisms and antiprisms, there are also 75 uniform compound polyhedra.

In other fields

Шаблон:Seealso Seventy-five is:

References

Шаблон:Reflist

Шаблон:Integers