Seven | 7 (angolul)
Keresés: " Seven " OR " 7 ", a következő helyen NRICH | PLUS | maths.org | Google
Definíció (alapfok)
The seventh counting number, the fourth prime number, the first hexahedral number. It is the third Mersenne number and the second Mersenne prime. It has the property that 7!+1 is a square (only 4,5 and 7 have this property). Its Fermat quotient is a square (the only other number for which this is the case is 3). It is the third Lucky number. 7 colours are sufficient to colour any map on a torus. φ(7)=6, d(7)=2, σ(7)=8 .
Kapcsolatok
- Bővítés:
- (en) 0-9
- Hivatkozás:
- (en) Fermat quotient
- (en) Lucky number
- (en) Mersenne number
- (en) Mersenne prime
- (en) Seven colour theorem
- Erre hivatkozik:
- (en) Heptagon
Támogatók: EU Socrates Minerva, HeyMath!, Cambridge University Press