31313
domain: N
Appears in sequences
- Octal palindromes which are also primes.at n=30A006341
- Palindromes of the form k*(k+8).at n=6A028568
- "Sloping binary representation" of powers of 3 (A000244), slope = -1.at n=23A037095
- Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 3,1.at n=4A037589
- a(n) is the smallest composite number c such that A002110(n) + c is prime.at n=38A038771
- Base-10 palindromes that starts with 3.at n=35A043038
- Palindromic brilliant numbers.at n=16A084350
- Palindromic hypotenuses in primitive Pythagorean triples.at n=33A087456
- a(n) = prime(n)*prime(n+2).at n=39A090076
- Semiprimes in A103376.at n=21A103396
- Palindromic primes in base 4 (written in base 4).at n=13A117699
- Palindromic primes in base 5 (written in base 5).at n=15A117700
- Reverse binary expansion of the Fibonacci numbers.at n=21A143250
- a(n) = prime(n) times the n-th nonnegative noncomposite.at n=41A176098
- Numbers k such that exactly three d in the range d <= k/2 exist which divide binomial(k-d-1,d-1) and which are not coprime to k.at n=21A178099
- List of primitive words over the alphabet {1,3}.at n=42A213970
- Palindromic composite numbers starting with a digit 3.at n=23A222726
- Start with 1. Successive digits in the sequence must differ by 2. Adjoin the smallest number not yet in the sequence.at n=42A228328
- Palindromes m such that m*(sum of digits of m) is also a palindrome.at n=35A229805
- Minimal nested palindromic base-5 primes with seed 3; see Comments.at n=2A262643