A074262 Positions of '11' in Kolakoski sequence A000002.

4, 13, 16, 22, 28, 31, 40, 48, 51, 58, 67, 70, 78, 85, 94, 97, 103, 112, 115, 121, 124, 130, 133, 140, 148, 157, 160, 167, 175, 178, 184, 190, 193, 201, 208, 217, 220, 226, 229, 238, 244, 247, 253, 256, 265, 271, 274, 283, 291, 294, 303, 310, 319, 322, 328

Offset: 1

Author

Jon Perry, Sep 20 2002

Keywords

• nonn
• easy

Examples

			Kolakoski sequence begins 1,2,2,1,1,2,1,2,2,1,2,2,1,1,... so 4 and 13 are in this sequence.
		

Links

• Nathaniel Johnston, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A074263.

Programs

Mathematica

a2 = {1, 2, 2}; Do[ a2 = Join[a2, {1 + Mod[n - 1, 2]}], {n, 3, 300}, {i, 1, a2[[n]]}]; Split[a2] /. {1, 1} -> {0, 1} // Flatten // Position[#, 0]& // Flatten (* Jean-François Alcover, Jun 18 2013 *)

Extensions

Extended and offset changed by Nathaniel Johnston, May 02 2011