131131

Appears in sequences

• Strong pseudoprimes to base 53.at n=29A020279
• Concatenation of n-th prime and its reverse.at n=31A067087
• Record-setting differences between adjacent elements of the Mian-Chowla sequence variant A051788.at n=44A080223
• Smallest palindromic multiple of (n with trailing 0's omitted, A004151) using only nonzero digits of n; all digits must appear; or 0 if no such number exists.at n=12A083960
• Smallest palindromic multiple of 2n-1 beginning with the digit string of 2n-1; or 0 if no such number exists.at n=6A083964
• Indices of centered heptagonal numbers (A069099) which are also heptagonal numbers (A000566).at n=5A133272
• Double primes: concatenation of the n-th prime with itself.at n=31A176597
• a(n) has generating function 1/((1-x)^k*(1-x^2)^(k*(k-1)/2)) for k=7.at n=8A181479
• a(n,k) equals the number of semistandard Young tableaux with shape of a partition of n and maximal element <= k.at n=34A191714
• Composite numbers whose multiplicative digital root is 9.at n=36A201024
• Number of semistandard Young tableaux over all partitions of 8 with maximal element <= n.at n=7A210430
• Dates after Jan 01 00 in chronological order which are palindromic when they are written in the format DD.MM.YY. The terms are listed as numbers (without the dots). Leading zeros of the terms are suppressed.at n=10A210888
• List of imprimitive words over the alphabet {1,3}.at n=12A213973
• Non-primitive words on {1,2,3}.at n=25A239018
• Palindromes p = A002113(n) whose index n is a substring of p.at n=13A248753
• a(n) = 2^n + prime(n).at n=16A265160
• Least number x such that x^n has n digits equal to k. Case k = 2.at n=37A285449
• a(n) = Sum_{d|n} prime(n/d)^d.at n=16A309368
• Smallest palindromic number >= 2^n.at n=17A333016
• Numbers that are a proper substring of the concatenation (with repetition) in decreasing order of their prime factors.at n=7A378950