428544

Appears in sequences

• Number of subsets of integers 1 through n (including the empty set) containing no pair of integers that share a common factor.at n=41A084422
• a(n) = ((9 + sqrt(5))^n - (9 - sqrt(5))^n)/(2*sqrt(5)).at n=5A153886
• Numbers k such that sigma(tau(k)) = rad(k).at n=13A173582
• Number of length n+3 0..2 arrays with at most one downstep in every n consecutive neighbor pairs.at n=28A255110