556640

Appears in sequences

• a(0)=1, a(1)=2; a(2n) = 2*a(2n-1)+1; a(2n+1) = a(2n) + x, where x is the least number not yet the difference of two terms.at n=33A111328
• Composite numbers m such that Product_{i=1..k} (p_i/(p_i-1)) / Sum_{i=1..k} (p_i/(p_i+1)) is an integer, where p_i are the k prime factors of m (with multiplicity).at n=24A230112
• Triangle, read by rows, each row n being defined by g.f. Product_{k=1..n} (k + x + 2*k*x^2), for n >= 0.at n=53A322891