31513

Properties

Appears in sequences

• a(n) = s(1)*t(n) + s(2)*t(n-1) + ... + s(k)*t(n-k+1), where k = [ n/2 ], s = (natural numbers >= 2), t = (Lucas numbers).at n=15A024873
• Palindromes of form k^2 + k + 7.at n=4A027723
• Palindromic prime concatenated with next palindromic prime is a prime.at n=1A030462
• Palindromic and prime Fibonacci-lucky numbers.at n=23A039679
• Base-10 palindromes that starts with 3.at n=37A043038
• Primes such that the sum of the squares of its digits is equal to the product of its digits.at n=5A067779
• Palindromic primes in which deleting the outside pair of digits yields a prime at every stage until finally a single-digit prime is obtained.at n=12A071119
• Palindromic primes with prime middle digit.at n=24A076611
• Palindromic primes = 1 mod 4.at n=24A081220
• Palindromic primes with middle digit 5.at n=7A082441
• Palindromic prime units W appearing twice in first-order fractal palindromic primes WmW.at n=26A082598
• Duplicate of A071119.at n=12A082805
• Palindromes which are prime and the sum of the digits is also prime.at n=31A082806
• Palindromic primes p with property that another palindromic prime with as many digits can be obtained by using all the digits of p with a different frequency >=1 (every digit is used at least once).at n=18A082807
• Palindromic primes which are a member of a twin prime pair.at n=18A083840
• 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=8A083842
• Least palindromic prime that strictly encloses the n-th palindromic prime, or 0 if no such prime exists.at n=7A084412
• Smallest palindromic prime built using the palindromes with odd number of digits as central digits.at n=14A087364
• Palindromic hypotenuses in primitive Pythagorean triples.at n=34A087456
• 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=20A088270