A308148 Number of length-n binary words avoiding (5+sqrt(5))/2-powers.

1, 2, 4, 8, 14, 26, 48, 88, 160, 292, 532, 966, 1756, 3194, 5810, 10552, 19182, 34868, 63376, 115172, 209316, 380422, 691384, 1256538, 2283666, 4150402, 7542974, 13708740

Offset

0,2

Comments

An e-power, where e is a real number, is a word of length n and period p such that n/p >= e. To avoid an e-power means that no subword (contiguous block) is an e-power.

Links

Table of n, a(n) for n=0..27.

Example

For n = 4, all length-4 binary words avoid (5+sqrt(5))/2 = 3.618... powers except 0000 and 1111.

Crossrefs

Cf. A296184 (5+sqrt(5))/2).

Sequence in context: A054193 A305003 A117633 * A273154 A135491 A164154

Adjacent sequences: A308145 A308146 A308147 * A308149 A308150 A308151

Keyword

nonn,more

Author

Jeffrey Shallit, May 14 2019

Status

approved