21091

Appears in sequences

• Composite numbers divisible by the palindromic sum of their prime factors (counted with multiplicity).at n=34A046358
• Odd numbers divisible by the palindromic sum of their prime factors (counted with multiplicity).at n=8A046359
• Composite a(n) divided by the palindromic sum of its prime factors is a palindrome (counted with multiplicity).at n=4A046361
• Number of trees with n nodes and 5 leaves.at n=19A055292
• a(n) = Sum_{k=0..n} binomial(floor((n+1)/2), floor((k+1)/2)) * 5^k.at n=6A097176
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 0), (0, -1, 1), (0, 1, -1), (1, 1, 1)}.at n=8A149692
• Numbers k = p*q*r (p, q, r prime) congruent to 0 mod p+q+r.at n=27A160394
• Number of zero-sum -n..n arrays of 5 elements with adjacent element differences also in -n..n.at n=8A202255
• Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 30", based on the 5-celled von Neumann neighborhood.at n=15A274487
• Odd squarefree composite numbers k, divisible by the sum of their prime factors, sopfr (A001414).at n=18A308643
• Sum of the smallest parts of the partitions of n into 10 parts.at n=50A326589
• Centered 30-gonal numbers.at n=37A389799