25819

Properties

Appears in sequences

• Quadruples of different integers from [ 1,n ] with no global factor.at n=29A015622
• Quadruples of different integers from [ 2,n ] with no global factor.at n=29A015627
• a(n) = Sum_{a(k): k=0,1,2,...,n-4,n-2,n-1}; a(n-3) is not a summand; initial terms are 1,1,3.at n=17A049866
• Primes p such that the sum of the digits of p is not prime, but the sum of each digit raised to the 4th power is prime.at n=20A091368
• Primes p whose period of reciprocal equals (p-1)/13.at n=5A098680
• Numbers n such that P(13*n) is prime, where P(n) is the unrestricted partition number.at n=19A113518
• Numbers whose square starts with 4 identical digits.at n=25A132391
• Number of 3 X n 0..1 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.at n=32A223950
• Primes p congruent to 1 modulo 13 such that x^13 = 2 has a solution modulo p.at n=16A275773
• Least prime q such that (q-p)/(r-q), where p<q<r are three consecutive primes, produces a new ratio <= 1, arranged by Farey fractions A038566/A038567.at n=40A279066
• Numbers k such that 10^k - 401 is prime.at n=20A288821
• Numbers k such that (32*10^k + 319)/9 is prime.at n=19A293856
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + n*b(n-1), where a(0) = 1, a(1) = 2, b(0) = 3, b(1) = 4, and (a(n)) and (b(n)) are increasing complementary sequences.at n=15A296288
• Primes p such that, if b is the sum of digits of p, y = p mod b and x = (p-y)/b, then p-x*y, p+x*y, x+y and x-y are all prime.at n=45A342801
• Numbers whose square starts with exactly 4 identical digits.at n=24A346940
• Primes p such that 2*p-1 and (2*p-1)^2+(2*p)^2 are also prime.at n=31A347165
• Primes p such that, if q is the next prime, p + q^2 is a prime times a power of 10.at n=23A352837
• a(n) is the first prime p such that, with q the next prime, p + q^2 is 10^n times a prime.at n=2A352848
• Smallest number with shortest addition-multiplication chain of length n.at n=11A383001
• Consecutive states of the linear congruential pseudo-random number generator 20403*s mod 2^15 when started at s=1.at n=7A384196