27578

Appears in sequences

• Expansion of (1-x+2*x^3-sqrt(1-2*x-3*x^2+4*x^3-4*x^4))/(2*x^2).at n=14A229733
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 238", based on the 5-celled von Neumann neighborhood.at n=43A270986
• Take a squarefree semiprime and take the difference of its prime factors. If it is a squarefree semiprime repeat the process. Sequence lists the squarefree semiprimes that generate other squarefree semiprimes only in the first k steps of this process. Case k = 5.at n=12A296812
• Expansion of Product_{k>=1} (1 + x^k)^A001001(k).at n=10A301777
• Number of perfect-powers x in the range 2^n <= x < 2^(n+1).at n=32A377435