21812

Appears in sequences

• Expansion of Product_{k>=1} (1 - x^k)^12.at n=33A000735
• Even palindromes in which parity of digits alternates.at n=29A030149
• Base-10 palindromes that start with 2.at n=40A043037
• Palindromic even lucky numbers.at n=27A045960
• Palindromes with exactly 5 prime factors (counted with multiplicity).at n=28A046331
• Palindromic untouchable numbers.at n=26A048187
• Least palindromic multiple of composite(n), or 0 if no such number exists.at n=53A110750
• Palindromes which are sums of two consecutive primes.at n=15A162571
• The number of boundary edges for all ordered trees with n edges.at n=8A228178
• Number of orbits of Aut(Z^7) as function of the infinity norm n of the representative lattice point of the orbit, when the cardinality of the orbit is equal to 13440.at n=42A266398
• a(1) = 0, a(2) = 1; and for n > 2, a(n) = 2*a(A285712(n)) + [1 == (n mod 3)].at n=26A292591
• Irregular triangular array read by rows. T(n,k) is the number of forests on n unlabeled nodes with exactly k distinct isomorphism classes of trees.at n=64A336167
• Fourier coefficients of the modular form (1/t_{6a}) * sqrt( 1-12*sqrt(-3)/t_{6a} ) * F_{6a}^6.at n=33A341563
• Palindromes that can be written as the sum of two palindromic primes.at n=36A356824