414417

Appears in sequences

• Numbers k such that k and k^2 use only the digits 1, 4, 7, 8 and 9.at n=18A137058
• Odd numbers n divisible by 3 such that for all k >= 1 the numbers n*2^k + 1 and n*2^(k+1) + 1 do not form a pair of primes.at n=30A243857