Jump to content

145 (number): Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
Tags: Reverted Mobile edit Mobile web edit
Undid revision 1155383450 by 24.78.61.251 (talk)
Line 6: Line 6:
'''145''' ('''one hundred [and] forty-five''') is the [[natural number]] following [[144 (number)|144]] and preceding [[146 (number)|146]].
'''145''' ('''one hundred [and] forty-five''') is the [[natural number]] following [[144 (number)|144]] and preceding [[146 (number)|146]].


== In mathematics =
== In mathematics ==
* Although composite, 145 is a [[Fermat pseudoprime]] to sixteen bases with b < 145 x . In four of those bases, it is a [[strong pseudoprime]]: 1, 12, 17, and 144.
* Although composite, 145 is a [[Fermat pseudoprime]] to sixteen bases with b < 145. In four of those bases, it is a [[strong pseudoprime]]: 1, 12, 17, and 144.
* Given 145, the [[Mertens function]] returns [[0 (number)|0]].<ref>{{Cite web|url=https://oeis.org/A028442|title=Sloane's A028442 : Numbers n such that Mertens' function is zero|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-28}}</ref>
* Given 145, the [[Mertens function]] returns [[0 (number)|0]].<ref>{{Cite web|url=https://oeis.org/A028442|title=Sloane's A028442 : Numbers n such that Mertens' function is zero|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-28}}</ref>
* 145 is a [[pentagonal number]]<ref>{{Cite web|url=https://oeis.org/A000326|title=Sloane's A000326 : Pentagonal numbers|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-28}}</ref> and a [[centered square number]].<ref>{{Cite web|url=https://oeis.org/A001844|title=Sloane's A001844 : Centered square numbers|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-28}}</ref>
* 145 is a [[pentagonal number]]<ref>{{Cite web|url=https://oeis.org/A000326|title=Sloane's A000326 : Pentagonal numbers|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-28}}</ref> and a [[centered square number]].<ref>{{Cite web|url=https://oeis.org/A001844|title=Sloane's A001844 : Centered square numbers|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-28}}</ref>

Revision as of 03:11, 18 May 2023

← 144 145 146 →
Cardinalone hundred forty-five
Ordinal145th
(one hundred forty-fifth)
Factorization5 × 29
Divisors1, 5, 29, 145
Greek numeralΡΜΕ´
Roman numeralCXLV
Binary100100012
Ternary121013
Senary4016
Octal2218
Duodecimal10112
Hexadecimal9116

145 (one hundred [and] forty-five) is the natural number following 144 and preceding 146.

In mathematics

  • Although composite, 145 is a Fermat pseudoprime to sixteen bases with b < 145. In four of those bases, it is a strong pseudoprime: 1, 12, 17, and 144.
  • Given 145, the Mertens function returns 0.[1]
  • 145 is a pentagonal number[2] and a centered square number.[3]
  • . 145 is the fourth number that is the sum of two different pairs of squares. Also, 145 is the result of 34 + 43, making it a Leyland number.
  • , making it a factorion.[4] The only other numbers that have the property that they are the sum of the factorials of their digits are 1, 2 and 40585.[4]
  • , making 145 the smallest number that can be written as the sum of a perfect square and a factorial in more than 2 distinct ways. The next number with this property is 46249.[5]

In the military

In sports

In transportation

In other fields

145 is also:

See also

References

  1. ^ "Sloane's A028442 : Numbers n such that Mertens' function is zero". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
  2. ^ "Sloane's A000326 : Pentagonal numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
  3. ^ "Sloane's A001844 : Centered square numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
  4. ^ a b "Sloane's A014080 : Factorions". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
  5. ^ "A359013 - OEIS". oeis.org. Retrieved 2022-12-11.
  6. ^ "1938 Delahaye 145 le mans Slot Car 1/32". www.tertrerouge-racingcars.com. Archived from the original on 16 September 2008. Retrieved 14 January 2022.
  7. ^ "Ferry Schedules & Maps - Ferry | Golden Gate".
  8. ^ "Route 145". London Bus Routes.