18281

Appears in sequences

• Palindromic Super-2 Numbers.at n=31A032750
• Period of 1/n in sequence A033938.at n=9A033939
• a(n) = C(n+2,3) + 2*C(n,2) + 2*(n-2).at n=44A034857
• Composite palindromes whose sum of prime factors is palindromic (counted with multiplicity).at n=28A046354
• Composite palindromes with only palindromic prime factors whose sum is palindromic (counted with multiplicity).at n=11A046357
• Palindromes with exactly 2 palindromic prime factors (counted with multiplicity), and no other prime factors.at n=26A046376
• Palindromes with exactly 2 distinct palindromic prime factors.at n=22A046408
• Least k such that gcd(prime(k+1)-1, prime(k)-1) = 2n.at n=23A067605
• Numbers n for which there are exactly nine k such that n = k + reverse(k).at n=34A072433
• Expansion of e.g.f. (1+x)*exp(4*x)*cosh(x).at n=6A082308
• Palindromic brilliant numbers.at n=14A084350
• Number of (3412,1234)-avoiding involutions in S_n.at n=30A085583
• Palindromic hypotenuses in primitive Pythagorean triples.at n=29A087456
• All palindromes of length greater than 1 in the decimal expansion of e, ordered by the ending position of the palindrome. Multiple terms ending at the same position are ordered by the starting position of the palindrome.at n=1A099052
• Brilliant numbers (A078972) whose digit reversal is the product of 2 palindromes greater than 1.at n=23A115681
• Palindromes equal to the sum of a prime number with its index.at n=32A115888
• Numbers k such that k concatenated with k-1 gives the product of two numbers which differ by 7.at n=3A116152
• Numbers k such that k concatenated with k+5 gives the product of two numbers which differ by 5.at n=2A116193
• Triangle T, read by rows, where column k equals column k of T^(k+1) shift down 1 row, with T(n,n)=T(n+1,n)=1 for n>=0.at n=47A121391
• Column 2 of triangle A121391, where column k of T=A121391 equals column k of T^(k+1) shift down 1 row.at n=7A121393