21564

Appears in sequences

• Number of distinct solutions of Sum_{i=1..3}(x(2i-1)*x(2i)) = 0 (mod n), with x() in 0..n-1.at n=14A180795
• Numbers n such that n!8-1 is prime.at n=57A204662
• Number of partitions p = [x(1), ..., x(k)], where x(1) >= x(2) >= ... >= x(k), of n such that min(x(i) - x(i-1)) <= number of distinct parts of p.at n=37A241824
• Numbers k such that Bernoulli number B_{k} has denominator 1919190.at n=14A295595
• G.f. = Phi*F^5, where Phi = g.f. for A028930, F = g.f. for A028959.at n=14A328536