18181

Properties

Appears in sequences

• Palindromic primes: prime numbers whose decimal expansion is a palindrome.at n=41A002385
• Numbers with mirror symmetry about middle.at n=24A006072
• Strobogrammatic primes.at n=5A007597
• Palindromic reflectable primes.at n=11A007616
• Strobogrammatic primes: the same upside down (calculator-style numerals).at n=13A018847
• Primes that contain digits 1 and 8 only.at n=7A020456
• Palindromic primes in which parity of digits alternates.at n=17A030150
• Palindromic lucky numbers.at n=41A031161
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 17.at n=7A031605
• Lucky numbers that are both palindromic and prime.at n=7A031881
• Palindromic Super-2 Numbers.at n=30A032750
• Undulating primes (digits alternate).at n=39A032758
• Euler transform of A027656(n-1).at n=30A035528
• Smallest n-digit prime containing only digits 1 and 8, or 0 if no such prime exists.at n=4A036935
• Erroneous version of A134996.at n=6A038136
• Palindromic and prime Fibonacci-lucky numbers.at n=19A039679
• Numerator of (1/n)*Sum_{k=0..n-1} 1/binomial(n-1,k) for n>0 else 0.at n=18A046878
• Primes resulting from procedure described in A048388.at n=32A048389
• Primes with consecutive digits that differ exactly by 7.at n=7A048404
• Numbers whose consecutive digits differ by 7.at n=25A048409