27969

Appears in sequences

• a(1) = 1; thereafter a(n+1) = floor(sqrt(2*a(n)*(a(n)+1))).at n=28A001521
• Least k such that the first k terms of the Kolakoski sequence (A000002) contain n more 2's than 1's.at n=18A025503
• Conjectured lower bound for the number of spheres of radius 1 that can be packed in a sphere of radius n.at n=32A121346
• Egyptian fraction representation for the cube root of 53.at n=3A132528
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 694", based on the 5-celled von Neumann neighborhood.at n=36A273411
• Position of first appearance of each integer in A088568 (number of 1's minus number of 2's in first n terms of A000002).at n=30A288605
• a(n) = index where A088568 (or equally A294448) first reaches or exceeds n in magnitude.at n=18A294449