A225681 Number of binary words of length n that are not rich.

0, 0, 0, 0, 0, 0, 0, 0, 4, 24, 92, 292, 850, 2276, 5766, 13968, 32690, 74368, 165442, 361104, 776116, 1646566, 3456030, 7189232, 14844878, 30464914

Offset

0,9

Links

Table of n, a(n) for n=0..25.

Amy Glen, Jacques Justin, Steve Widmer and Luca Q. Zamboni, Palindromic richness, arXiv:0801.1656 [math.CO]

Formula

2^n - A216264(n).

Crossrefs

Cf. A216264.

Sequence in context: A026977 A026952 A222670 * A259814 A009769 A119878

Adjacent sequences: A225678 A225679 A225680 * A225682 A225683 A225684

Keyword

nonn,more

Author

N. J. A. Sloane, May 16 2013

Status

approved