43 (number)

From Free net encyclopedia

(Redirected from -43 (number))

43 (forty-three) is the natural number following 42 and preceding 44.

<< 40 41 42 43 44 45 46 47 48 49 >>

Cardinal 43
forty-three
Ordinal 43rd
forty-third
Factorizationprime
Roman numeralXLIII
Binary101011
Hexadecimal2B

Contents

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 the smallest prime that is not a Chen prime.

43 is the fourth term of Sylvester's sequence.

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... Template: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 chemical element with the atomic number 43 (technetium) is the element with the lowest ordinal number, which does not possess stable isotopes. The technetium preceding element 42 (molybdenum) and the technetium following element 44 (ruthenium) have stable isotopes.

Astronomy

In other fields

Forty-three is also:

External links

eo:Kvardek tri fr:43 (nombre) ko:43 ia:43 it:Quarantatré lt:43 (skaičius) nap:Quarantatrè nl:43 (getal) ja:43 no:43 (tall) pt:Quarenta e três ru:43 (число) sl:43 (število) fi:43 (luku) sv:43 (tal) zh:43