21671

Appears in sequences

• Take list of cubes, move left digit of each term to end of previous term.at n=24A032761
• Numbers n such that 141*2^n-1 is prime.at n=23A050596
• Numbers n such that sigma(sigma(n) - phi(n)) = phi(sigma(n) + phi(n)).at n=9A074876
• The point at which the powers of n merge on an 8-digit calculator.at n=45A216069
• Number of (n+4) X 11 0..1 matrices with each 5 X 5 subblock idempotent.at n=13A224689
• Number of partitions p of n such that (number of numbers in p of form 3k) > (number of numbers in p of form 3k+1).at n=46A241745
• a(n) = greatest k such that A155043(k+A262509(n)) < A155043(A262509(n)).at n=41A262909
• If n is 0, 1, or prime, a(n) = n; else a(n) = a(n-1) + a(n-2).at n=44A265822
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 419", based on the 5-celled von Neumann neighborhood.at n=31A272047
• G.f. is the cube of the g.f. of A006950.at n=18A273226
• Numbers k such that both k and k+2 are de Polignac numbers (A006285).at n=34A330284