A088950 Number of square-subwords in ternary representation of n.

0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 2, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 1, 2, 2, 1, 1, 1, 1, 0, 0, 0, 1, 2, 1, 1, 2, 4, 2, 1, 1, 2, 1, 0, 0, 0, 1, 1, 1, 1, 2, 2, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 2, 1, 0, 1, 1, 2, 1, 1, 1, 2, 1, 2, 2, 4, 4, 2, 2, 1, 2, 1, 1, 1, 2, 2, 2, 1, 1, 2, 1, 0, 0, 1, 1, 0, 1

Offset: 0

Author

Reinhard Zumkeller, Oct 25 2003

Keywords

• nonn
• base

Comments

A square-(sub)word consists of two nonempty identical adjacent subwords.

Examples

			n=90: a(90)=2 because 90 -> '10100' has 2 square-subwords: 00 and 1010.
		

Links

• Eric Weisstein's World of Mathematics, Squarefree Word

Crossrefs

Cf. A007089, A088951, A088952.

Programs

Mathematica

Table[SequenceCount[IntegerDigits[n, 3], {x__, x__}, Overlaps -> All], {n, 0, 100}] (* Vladimir Reshetnikov, May 17 2016 *)