18681

Appears in sequences

• Lucky numbers that are both palindromic and nonprime.at n=35A031880
• Palindromic Super-2 Numbers.at n=35A032750
• Denominators of continued fraction convergents to sqrt(954).at n=9A042847
• Numbers n for which there are exactly nine k such that n = k + reverse(k).at n=36A072433
• Beginning with 2, smallest palindrome >= the previous term such that every concatenation is a prime.at n=14A088093
• a(1) = 1, then the rearrangement of odd palindromes such that every concatenation is a prime for n > 1.at n=33A113578
• Start with 1 and repeatedly reverse the digits and add 38 to get the next term.at n=34A118634
• G.f. is the polynomial (1-x^3) * (1-x^6) * (1-x^9) * (1-x^12) * (1-x^15) * (1-x^18) / (1-x)^6.at n=22A162539
• G.f. is the polynomial (1-x^3) * (1-x^6) * (1-x^9) * (1-x^12) * (1-x^15) * (1-x^18) / (1-x)^6.at n=35A162539
• Palindromic Ulam numbers.at n=34A173542
• Number of (n+2) X (3+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000000 00000001 or 00001001.at n=4A259957
• Number of (n+2)X(5+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000000 00000001 or 00001001.at n=2A259959
• T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000000 00000001 or 00001001.at n=23A259962
• T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000000 00000001 or 00001001.at n=25A259962
• Palindromes (A002113) in A157037.at n=32A353703