Unsolved Problems

Showing 101-122 of 122 problems (Page 3 of 3)

NT-087
Open

Agoh-Giuga Conjecture

Is $p$ prime if and only if $pB_{p-1} \equiv -1 \pmod{p}$ for the Bernoulli number $B_{p-1}$?...

L4
Number Theory
334
25
NT-088
Open

Elliott-Halberstam Conjecture

Do primes distribute uniformly in arithmetic progressions up to nearly $x$ (instead of $x^{1/2}$)?...

L5
Number Theory
412
32
NUM-001
Open

Singmaster's Conjecture

Is there a finite upper bound on multiplicities of entries >1 in Pascal's triangle?...

L4
Number Theory
178
14
NUM-002
Open

Odd Perfect Numbers

Do any odd perfect numbers exist?...

L5
Number Theory
412
32
NUM-003
Open

Infinitude of Perfect Numbers

Are there infinitely many perfect numbers?...

L5
Number Theory
345
27
NUM-004
Open

Quasiperfect Numbers

Do quasiperfect numbers exist?...

L4
Number Theory
167
13
NUM-005
Open

Lychrel Numbers

Do Lychrel numbers exist in base 10?...

L3
Number Theory
234
18
NUM-006
Open

Odd Weird Numbers

Do odd weird numbers exist?...

L4
Number Theory
189
15
NUM-007
Open

Infinitude of Amicable Pairs

Are there infinitely many pairs of amicable numbers?...

L4
Number Theory
212
17
NUM-008
Open

Pi Normality

Is π a normal number (all digits equally frequent in all bases)?...

L5
Number Theory
389
30
NUM-009
Open

Algebraic Number Normality

Are all irrational algebraic numbers normal?...

L5
Number Theory
201
16
NUM-010
Open

Gilbreath's Conjecture

Does iterating unsigned differences on prime sequence always yield 1 as first element?...

L4
Number Theory
156
12
NUM-011
Open

Lander-Parkin-Selfridge Conjecture

If Σᵢ aᵢᵏ = Σⱼ bⱼᵏ with m terms on left, n on right, is m+n ≥ k?...

L4
Number Theory
178
14
NUM-012
Open

Class Number Problem

Are there infinitely many real quadratic fields with class number 1 (unique factorization)?...

L5
Number Theory
198
16
NUM-013
Open

Hilbert's 12th Problem

Extend Kronecker-Weber theorem to abelian extensions of arbitrary number fields....

L5
Number Theory
187
15
NUM-014
Open

Leopoldt's Conjecture

Does the p-adic regulator of an algebraic number field never vanish?...

L5
Number Theory
156
12
NUM-015
Open

Siegel Zeros

Do Siegel zeros (real zeros of Dirichlet L-functions near s=1) exist?...

L5
Number Theory
234
18
NUM-016
Open

Schanuel's Conjecture

For e and π: are they algebraically independent? Is e+π, eπ, π^e, etc. transcendental?...

L5
Number Theory
287
22
NUM-017
Open

Euler-Mascheroni Constant Irrationality

Is the Euler-Mascheroni constant γ irrational? Transcendental?...

L5
Number Theory
323
25
NUM-018
Open

Littlewood Conjecture

For any α,β ∈ ℝ, is lim inf_{n→∞} n·||nα||·||nβ|| = 0?...

L5
Number Theory
189
15
NUM-019
Open

Four Exponentials Conjecture

If x₁,x₂ and y₁,y₂ are linearly independent over ℚ, is at least one of e^(xᵢyⱼ) transcendental?...

L5
Number Theory
167
13
NUM-020
Open

Integer Factorization Polynomial Time

Can integer factorization be done in polynomial time?...

L5
Number Theory
456
35