113311

Appears in sequences

• Concatenation of n-th prime and its reverse.at n=29A067087
• Odd palindromes which are semiprimes with an even number of digits.at n=21A132288
• Composite numbers whose multiplicative digital root is 9.at n=34A201024
• Maximal nonempty {1,3}-chunks of a 4-day-old string in a "Look and Say" sequence.at n=29A244047
• Palindromes in base 10 that are also palindromes in base 60.at n=20A262069
• a(n) = (tan(1*Pi/11))^(2*n) + (tan(2*Pi/11))^(2*n) + (tan(3*Pi/11))^(2*n) + (tan(4*Pi/11))^(2*n) + (tan(5*Pi/11))^(2*n).at n=3A275546
• Composite palindromes whose divisors > 1 are all nontrivial palindromes (i.e., palindromes with at least two digits).at n=23A329100
• Palindromes which are a concatenation of three palindromes, each of which has at least 2 digits.at n=3A368020
• a(n) = (32*n^4 + 80*n^3 + 40*n^2 - 20*n + 3)*(2*n + 1)*n/15.at n=5A376778
• Array read by ascending antidiagonals: A(n, k) = Sum_{j=0..k} tan(j*Pi/(1 + 2*k))^(2*n).at n=41A377657