210181

Appears in sequences

• Composite numbers having the same digits as their prime factors (with multiplicity), excluding zero digits.at n=32A176670
• Numbers n such that there are a, b with abs(sigma(a) - sigma(b)) = sigma(n) - n and a U b = n, where U is decimal concatenation.at n=35A239563
• a(n) = 2*F(n-1) + 2*F(n-3) + 10*F(n-5) + 9*F(n-8) where n >= 8 and F = A000045.at n=17A280932