43 (number)

From Biocrawler, the free encyclopedia.

43 is the natural number following 42 and preceding 44.

List of numbers — Integers << 40 41 42 43 44 45 46 47 48 49 >>
Cardinal	forty-three
Ordinal	43rd (forty-third)
Factorization	prime
Roman numeral	XLIII
Binary	101011
Hexadecimal	2B

In mathematics

Forty-three is the 14th smallest prime number. The previous is forty-one, with which it comprises a twin prime, the next is forty-seven. 43 is a centered heptagonal number.

Let a(0) = a(1) = 1, and thenceforth a(n) = (a(0)² + a(1)² + ... + a(n-1)²) / (n-1). This sequence continues 1 1 2 3 5 10 28 154... (sequence A003504 in OEIS). Amazingly, a(43) is the first term of this sequence that is not an integer.

Negative forty-three (-43) is a Heegner number.

In science

• The atomic number of technetium

In astronomy,

Messier object M43, a magnitude 7.0 H II region in the constellation of Orion, a part of the Orion Nebula, and also sometimes known as de Mairan's Nebula

The New General Catalogue object (http://www.ngcic.org/) NGC 43, a barred spiral galaxy in the constellation Andromeda

The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/SEsaros/SEsaros1-175.html) of the solar eclipse series which began on -1512 April 29 and ended on -232 June 5. The duration of Saros series 43 was 1280.1 years, and it contained 72 solar eclipses.

The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/LEsaros/LEsaros1-175.html) of the lunar eclipse series which began on -1481 August 27 and ended on 70 March 15. The duration of Saros series 43 was 1550.5 years, and it contained 87 lunar eclipses.

In other fields

Forty-three is also:

• The designation of Interstate 43, a freeway in Wisconsin.
• The code for direct dial international phone calls to Austria.
• Part of the title of the historical British comedy show Hancock's Forty-Three Minutes, starring Tony Hancock.
• Part of the title of a historical short story by Hershel Finman titled Forty-Three Rubles, about Rabbi Zvi Elimelech Spira.
• The year AD 43, 43 BC, and 1943.es:Cuarenta y tres

eo:Kvardek tri fr:Quarante-trois ko:43 ia:43 it:Quarantatré nl:43 (getal) ja:43 pt:Quarenta e três ru:43 (число) sl:43 (število) sv:43 (tal) zh:43

Wikipedia (http://en.wikipedia.org/wiki/Main_Page) 43_(number) (http://en.wikipedia.org/wiki/43_(number)) version history (http://en.wikipedia.org/w/index.php?title=43_(number)&action=history) GNU Free Documentation Lizenz (http://en.wikipedia.org/wiki/Wikipedia:Text_of_the_GNU_Free_Documentation_License) CC-by-sa (http://creativecommons.org/licenses/by-sa/2.5/)

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