A118270 Decimal expansion of Kolakoski constant.

7, 9, 4, 5, 0, 7, 1, 9, 2, 7, 7, 9, 4, 7, 9, 2, 7, 6, 2, 4, 0, 3, 6, 2, 4, 1, 5, 6, 3, 6, 0, 4, 5, 6, 4, 6, 2, 9, 8, 5, 7, 7, 1, 0, 0, 9, 8, 8, 6, 0, 6, 9, 6, 7, 2, 6, 5, 8, 8, 6, 7, 3, 7, 1, 5, 3, 8, 1, 4, 7, 7, 5, 0, 2, 4, 6, 0, 5, 0, 1, 5, 3, 6, 4, 2, 3, 2, 9, 4, 9, 7, 3, 1, 8, 7, 4, 4, 9, 2, 2, 5, 9, 7, 6, 5

Offset: 0

Author

Eric W. Weisstein, Apr 21 2006

Keywords

• nonn
• cons

Examples

			0.7945071927794792762...
		

Links

• Rabie A. Mahmoud, Hardware Implementation of Binary Kolakoski Sequence, Research Gate, 2015.
• Eric Weisstein's World of Mathematics, Kolakoski Sequence

Crossrefs

Cf. A000002.

Programs

Mathematica

A000002[n_] := (s = {1, 2, 2}; Do[AppendTo[s, Mod[k-1, 2] + 1], {k, 3, n}, {s[[k]]}] ; s); Take[ First[ RealDigits[ FromDigits[ {Rest[A000002[300] /. {1 -> 0, 2 -> 1}], 0}, 2]]], 105] (* Jean-François Alcover, Jul 28 2011 *)

Formula

Take the Kolakoski sequence (A000002) 1221121221.... Interpret the 2's as 1's and the 1's as 0's: 0110010110.... Interpret the result as a binary fraction: 0.110010110..._2.