Arithmétique Divisibilité

Z
x−1|x+ 3 x+ 2 |x2+ 2
Z2
xy = 3x+ 2y1
x+1 y=1 5x2−y2−4x−2y= 5
n∈N∗N n P
n N P
a∈Zb∈N∗q a −1
b
n∈N(abn−1)
bn+1
(ϕn)n∈N
ϕ0= 0, ϕ1= 1 ∀n∈N, ϕn+2 =ϕn+1 +ϕn
∀n∈N∗, ϕn+1ϕn−1−ϕ2
n= (−1)n
∀n∈N∗, ϕn∧ϕn+1 = 1
∀n∈N,∀m∈N∗, ϕn+m=ϕmϕn+1 +ϕm−1ϕn
∀m, n ∈N∗,pgcd(ϕn, ϕm+n) = pgcd(ϕn, ϕm)
pgcd(ϕm, ϕn) = pgcd(ϕn, ϕr)r
m n
pgcd(ϕm, ϕn) = ϕpgcd(m,n)
a b
a= 33 b= 24
a= 37 b= 27
a= 270 b= 105
a, b, d ∈Z
(∃u, v ∈Z, au +bv =d)⇐⇒ pgcd(a, b)|d
2n+ 4 3n+ 3 1,2,3
d, m ∈N
pgcd(x, y) = d
ppcm(x, y) = m
(x, y)∈N2

N2
pgcd(x, y) + ppcm(x, y) = x+y
N2
pgcd(x, y)=5
ppcm(x, y) = 60 x+y= 100 pgcd(x, y) = 10
a, b ∈Z
a∧b= 1 (a+b)∧ab = 1
pgcd(a+b, ppcm(a, b))
n∈N∗
(n2+n)∧(2n+ 1) = 1 (3n2+ 2n)∧(n+ 1) = 1
n∈N∗n+ 1 2n+ 1
n+ 1 |2n
n
a b c ∈Z
pgcd(a, bc) = pgcd(a, c)
a b
(u, v)∈Z2au +bv = 1
(u0, v0)
(u0+kb, v0−ka)
k∈Z
n∈N(an, bn)∈N2
(1 + √2)n=an+bn√2
a2
n−2b2 n
anbn
a b d ∈Nab
∃!(d1, d2)∈N2, d =d1d2, d1|a d2|b
n∈N
ai=i.n!+1
i∈ {1, . . . , n + 1}
n≥2N n N

4n3+ 6n2+ 4n+ 1 n∈N∗n4−n2+ 16 n∈Z
n
n n!+2
1 000
n≥2 2n−1
n
a > 1n > 0
an+ 1 n
a, b ∈N\ {0,1}n∈N∗
an+bnn
E={4k−1|k∈N∗}n∈E p ∈ P ∩ E p |n
p p =−1 mod 4
n∈N√n∈Q⇐⇒ ∃m∈N, n =m2
√2/∈Q√3/∈Q
x∈Qn∈N∗xn∈Zx∈Z
a, b ∈N∗m, n am=bn
c∈N∗a=cnb=cm
n p p
(E): xn+an−1xn−1+··· +a1x+a0= 0
x a0, a1, . . . , an−1
(E)
p∈ P α∈N∗pα
n∈N\ {0,1}n=QN
k=1 pαk
kn
n∈N\ {0,1}
n=
N
Y
i=1
pαi
i
d(n)n σ(n)
d(n) =
N
Y
i=1
(αi+ 1) σ(n) =
N
Y
i=1
pαi+1
i−1
pi−1

σ:Z→Nn∈Zn
p∈ P α∈N∗σ(pα)
a, b ∈Z
d ab
d=d1d2d1d2a b
a b σ(ab) = σ(a)σ(b)
σ(n)n
p∈ P n∈Zvp(n)p
n
v2(1 000!) = 994
vp(n!)
∀x∈R,bpxc
p=bxc
Pn > 0vp(n)
p n bxc
x π(x)
x
vp(n!) = P+∞
k=1 jn
pkk
2n
nQp∈P;p≤2npbln(2n)
ln pc
2n
n≤(2n)π(2n)
x
ln x= O(π(x)) x→+∞
p
∀k∈ {1,2, . . . , p −1}, p |p
k
∀n∈Z, np≡nmod p
n≥2
∀a∈ {1, . . . , n −1}, an−1≡1 [n]
n
n
n p n p2n p −1
n−1
∀a∈Z, an≡a[n]

x= 1 x6= 1
x−1|x+3 ⇐⇒ x+3
x−1= 1+ 4 x−1∈Z⇐⇒ x−1∈ D(4) = {1,2,4,−1,−2,−4}
S={2,3,5,0,−1,−3}
x=−2x6=−2
x+ 2 |x2+ 2 ⇐⇒ x2+2
x+2 =x−2 + 6 x+2 ∈Z⇐⇒ x+ 2 ∈ D(6) =
{1,2,3,6,−1,−2,−3,−6}
S={−1,0,1,4,−3,−4,−5,−8}
xy = 3x+ 2y⇐⇒ (x−2)(y−3) = 6
S={(3,9),(4,6),(5,5),(8,4),(1,−3),(0,0),(−1,1),(−4,2)}
x, y ∈Z∗
1
x+1 y=1 5⇐⇒ 5x+ 5y=xy ⇐⇒ (x−5)(y−5) = 25
S={(6,30),(10,10),(30,6),(4,−20),(−20,4)}
x2−y2−4x−2y= 5 ⇐⇒ (x−2)2−(y+ 1)2= 8
x2−y2−4x−2y= 5 ⇐⇒ (x−y−3)(x+y−1) = 8
x−y−3 = a
x+y−1 = b⇐⇒ x=a+b
2+ 2
y=b−a
2−1
S={(5,0),(5,−2),(−1,0),(−1,−2)}
P2=P×P d
n/d N n
P2=nN
a−1 = bq +r0≤r < b
abn−1 = (bq +r+ 1)bn−1 = qbn+1 +bn(r+ 1) −1
0≤bn(r+ 1) −1< bn+1
abn−1bn+1
q
n∈N∗
n= 1 ϕ2ϕ0−ϕ2
1= 0 −1 = −1
n≥1
ϕn+2ϕn−ϕ2
n+1 = (ϕn+ϕn+1)ϕn−ϕn+1(ϕn+ϕn−1) = ϕ2 n−ϕn+1ϕn−1=
HR −(−1)n= (−1)n+1
ϕn∧ϕn+1 = 1
uϕn+vϕn+1 = 1 u, v ∈Z
m∈N∗
m= 1 ϕn+1 =ϕ1ϕn+1 +ϕ0ϕnϕ1= 1 ϕ0= 0
n≥1
ϕn+m+1 =ϕ(n+1)+m=
HR ϕmϕn+2+ϕm−1ϕn+1 =ϕmϕn+1+ϕmϕn+ϕm−1ϕn+1 =ϕm+1ϕn+1+ϕmϕn
pgcd(ϕm+n, ϕn) = pgcd(ϕmϕn−1+ϕm−1ϕn, ϕn) = pgcd(ϕmϕn−1, ϕn) = pgcd(ϕm, ϕn)
ϕn∧ϕn−1= 1
∀q∈Nϕm∧ϕn=ϕm+qn ∧ϕn
pgcd(ϕm, ϕn) = pgcd(ϕn, ϕr)
m=nq +r q ∈N