21553

Appears in sequences

• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 86 ones.at n=26A031854
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 427", based on the 5-celled von Neumann neighborhood.at n=30A271904
• Triangle read by rows: Number of oriented graphs on n nodes with k components.at n=30A281446
• a(n) = 2*a(n-1) - a(n-3) + 2*a(floor(n/2)) + 3*a(floor(n/3)) + ... + n*a(floor(n/n)), where a(0) = 1, a(1) = 1, a(2) = 1.at n=14A298408