20939

Properties

Appears in sequences

• Primes that remain prime through 3 iterations of function f(x) = 3x + 2.at n=17A023277
• Primes that remain prime through 4 iterations of function f(x) = 3x + 10.at n=16A023310
• Irregular primes with irregularity index three.at n=32A060975
• Integer part of log(n!)^log(n).at n=16A062421
• Nearest integer to log(n!)^log(n).at n=16A062422
• Beginning with 2 the smallest prime greater than the previous term such that the difference of successive terms is a distinct square.at n=14A084710
• Row sums of triangle A086606: the sum of the first n terms of the n-th self-convolution of the sequence formed by flattening triangle A086606.at n=7A086608
• Number of consecutive prime runs of 3 primes congruent to 1 mod 4 below 10^n.at n=6A092642
• Primes that do not divide any term of the Lucas 4-step sequence A073817.at n=19A106300
• Least k>p such that (kp)^3 divides (p-1)^(kp)^2+1 for prime p = A000040(n).at n=6A128677
• Primes congruent to 16 mod 61.at n=37A142814
• a(n) = 58*n^2 + 1.at n=19A158666
• Primes p such that 2p+1, 3p+2 and 5p-2 are also primes.at n=21A178068
• Primes of the form 2*n^2+26*n+11.at n=28A243888
• Numerators of upper primes-only best approximates (POBAs) to the golden ratio, phi (A001622); see Comments.at n=13A265798
• Least number x such that x^n has n digits equal to k. Case k = 3.at n=20A285450
• G.f.: Sum_{n>=0} (n+1) * x^n * (1 + x^n)^n.at n=76A326002
• Primes whose square is the sum of the cubes of four primes, not necessarily distinct.at n=7A353263
• Prime numbersat n=2355