19027

Appears in sequences

• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 27 ones.at n=9A031795
• Triangle: Number of asymmetric self-converse semigroups of order n with k idempotents.at n=21A058169
• Integers n > 10553 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 10553.at n=15A063061
• Semiprimes which are the sum of three distinct positive cubes in two or more distinct ways.at n=25A180089
• G.f. A(x) satisfies: A(A(x)) - A(A(x))^2 = x + x^2.at n=11A182399
• G.f.: exp( Sum_{n>=1} A056789(n)*x^n/n ), where A056789(n) = Sum_{k=1..n} lcm(k,n)/gcd(k,n).at n=16A226455
• a(n) = floor(Sum_{k=n^3..(n+1)^3} k^(1/3)).at n=18A374384
• a(n) = p(n)*p(n+1)*(p(n+1) - p(n)) - 1, where p(n) = prime(n).at n=18A383241