The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A230177 Number of binary strings of length n avoiding "squares" (that is, repeated blocks of the form xx) with |x| > 3. 4
 1, 2, 4, 8, 16, 32, 64, 128, 240, 464, 866, 1642, 3048, 5720, 10642, 19868, 36894, 68722, 127630, 237324, 440594, 818584, 1519802, 2822630, 5240262, 9730478, 18065252, 33542006, 62272196, 115616582, 214646190, 398507348, 739840164, 1373551484, 2550032248 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS R. C. Entringer, D. E. Jackson and J. A. Schatz, On nonrepetitive sequences, J. Combin. Theory Ser. A. 16 (1974), 159-164. Nathaniel Johnston, C code for computing this sequence EXAMPLE a(8) = 256 - 16 = 240 because there are 256 binary strings of length 8, 16 of which contain a repeated block of length 4: 00000000, 00010001, 00100010, ..., 11111111. CROSSREFS Cf. A229614, A230127, A230216. Sequence in context: A229617 A306316 A275061 * A216264 A054045 A008860 Adjacent sequences: A230174 A230175 A230176 * A230178 A230179 A230180 KEYWORD nonn AUTHOR Nathaniel Johnston, Oct 11 2013 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified March 30 13:38 EDT 2023. Contains 361621 sequences. (Running on oeis4.)