19290

Appears in sequences

• Numbers k such that k*3^k + 1 is prime.at n=11A006552
• Numbers whose natural logarithm, in base 10, starts with 10 distinct digits.at n=8A113509
• G.f.: A(x) = exp( Sum_{n>=1} G_n(x^n)^2 * x^n/n ) such that G_n(x^n) = Product_{k=0..n-1} A(u^k*x) where u is an n-th root of unity.at n=8A203266
• Numbers n such that sigma(n) is a Fibonacci number.at n=12A272412
• a(n) is the least k such that sigma(k) is a Fibonacci number when k is the product of n distinct primes, or 0 if no such k exists.at n=3A290936
• Numbers k such that Bernoulli number B_{k} has denominator 14322.at n=26A295588