19891

Properties

Appears in sequences

• Palindromic primes: prime numbers whose decimal expansion is a palindrome.at n=44A002385
• Lesser of two consecutive palindromes, both of which are prime.at n=11A032593
• Number of partitions satisfying cn(0,5) <= cn(2,5) + cn(3,5).at n=37A039840
• a(n) = A047980(2n).at n=38A047981
• Palindromic primes containing no pair of consecutive equal digits.at n=38A050784
• Discriminants of imaginary quadratic fields with class number 25 (negated).at n=33A056987
• Primes p such that q-p = 22, where q is the next prime after p.at n=37A061779
• Smallest palindromic prime with digit sum = n, or 0 if no such prime exists.at n=27A070245
• Numbers n for which there are exactly ten k such that n = k + reverse(k).at n=16A072434
• For a prime p, let k(p) be the least k such that 2kp+1 is prime. Sequence gives primes for which k(p) exceeds k(q) for all primes q < p.at n=17A074884
• Palindromic primes with nonprime middle digit.at n=21A076613
• Palindromic primes with successive increasing difference: a(k)-a(k-1) < a(k+1)- a(k).at n=7A078790
• Palindromic primes with middle digit 8.at n=5A082444
• Palindromic primes using only nonprime digits (0,1,4,6,8,9).at n=11A083185
• Diagonal of A083464.at n=16A083465
• Palindromic primes which are a member of a twin prime pair.at n=16A083840
• Palindromic primes p such that p-2 is also a prime: members of A083840 which are the larger member of a twin prime pair.at n=7A083842
• Duplicate of A083185.at n=11A084987
• Palindromic primes that yield a prime when sandwiched between two 3's. (Prefixing and suffixing a -three' on both sides yields another pal prime).at n=16A088270
• Primes p such that p-3 and p+3 are divisible by a cube.at n=19A089201