50007

Appears in sequences

• a(n) = [ a(n-1)/a(1) + a(n-1)/a(2) + ... + a(n-1)/a(n-1) ] for n >= 3, with initial terms 1,1.at n=12A022854
• Numbers k such that j(k)*phi(k) = sigma(phi(k)), j(k) = A033831(k).at n=37A033856
• Schroeder pseudoprimes: Composites k that divide the k-th Schroeder number A001003(k-1).at n=30A075764
• Multiples of 3 in which there is no common digit in successive terms.at n=30A083491
• a(1) = 1 then the least multiple of odd numbers not odd multiples of 5, (3,7,9,11,13,17,19,21,23,27,29,...) such that every partial concatenation is noncomposite.at n=31A110433
• Number of length-4 0..n arrays with no repeated value differing from the previous repeated value by other than plus two or minus 1.at n=13A269641
• Number of nondeterministic Dyck bridges of length 2*n.at n=5A368164