27210

Appears in sequences

• Numbers k such that the three second-degree cyclotomic polynomials x^2 + 1, x^2 - x + 1 and x^2 + x + 1 are simultaneously prime when evaluated at x=k.at n=20A087277
• a(n) = 121*n^2 - n.at n=14A157960
• Numbers n such that 2^n divided by the number of digits of 2^n is an integer.at n=45A158520
• a(n) = 225*n^2 - 15.at n=10A158559
• a(n) = binary code (shown here in decimal) of the position of natural number n in the beanstalk-tree A218776.at n=37A218615
• a(n) = binary code (shown here in decimal) of the position of the predecessor of the natural number pair (2n,2n+1) in the compact beanstalk-tree A218780.at n=19A218791
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 547", based on the 5-celled von Neumann neighborhood.at n=29A272840
• Coefficients in the expansion of ([s] + [2s]x + [3s]x^2 + ...)/([r] + [2r]x + [3r]x^2 + ...); [ ] = floor, r = sqrt(3), s = r/(1-r).at n=37A279630