85073

Appears in sequences

• For n > 1, a(n) is the smallest number such that n-th concatenation is prime and the smallest palindrome beginning with (but not equal to) this concatenation is also prime.at n=28A088090
• Integers n not of form 3m+1 such that for any integer k>0, n*10^k-1 has a divisor in the set { 7, 11, 13, 37 }.at n=19A243974
• Numbers k such that 2^sigma(k) == -1 (mod k).at n=4A276238
• Numbers k such that 2^psi(k) == -1 (mod k) where psi(k) = A001615(k).at n=11A291164
• Numbers m that divide 4^(m + 1) + 1.at n=4A329168