1138830

Appears in sequences

• Numbers k such that k-1, k+1, 2*k-1, 2*k+1, 4*k-1 and 4*k+1 are all prime.at n=7A069175
• Numbers n such that n-1, n+1, 2n-1, 2n+1, 4n-1, 4n+1, 8n-1 and 8n+1 are all prime.at n=1A069176
• Smallest number with n distinct prime divisors which is the average of a twin prime pair.at n=6A075590
• Smallest squarefree number with n prime divisors which is the average of a twin prime pair.at n=5A075591
• Duplicate of A075590.at n=6A088255
• Products of 7 distinct primes (squarefree 7-almost primes).at n=11A123321
• Numbers that are divisible by exactly 7 distinct primes.at n=12A176655
• Unitary totient superdeficient numbers: numbers n > 1 such that s(n)/n < s(m)/m for all m < n, where s is the sum of iterated uphi (A047994).at n=14A291174
• a(n) is the least k such that there are exactly n divisors d of k for which k/d-d is prime.at n=38A340729