Preface |
|
xi | |
Permissions |
|
xiv | |
|
|
1 | (9) |
|
1.1 Powers, factors, periods, exponents |
|
|
2 | (3) |
|
|
5 | (1) |
|
|
6 | (4) |
|
|
10 | (22) |
|
|
10 | (6) |
|
2.2 Infinite words (sequences) |
|
|
16 | (2) |
|
2.3 Morphisms and morphic words |
|
|
18 | (1) |
|
2.4 Some famous sequences |
|
|
18 | (10) |
|
2.5 Properties of sequences |
|
|
28 | (2) |
|
2.6 Proving properties of words through exhaustive search |
|
|
30 | (1) |
|
|
31 | (1) |
|
3 Number representations and numeration systems |
|
|
32 | (15) |
|
3.1 Base-k representation |
|
|
32 | (1) |
|
3.2 Fibonacci representation |
|
|
33 | (1) |
|
3.3 Tribonacci representation |
|
|
34 | (1) |
|
|
35 | (1) |
|
3.5 Ostrowski representation |
|
|
36 | (11) |
|
|
47 | (15) |
|
|
47 | (2) |
|
|
49 | (1) |
|
|
49 | (1) |
|
4.4 Operations on automata |
|
|
50 | (2) |
|
|
52 | (1) |
|
|
53 | (1) |
|
4.7 Automata with multiple inputs |
|
|
54 | (1) |
|
4.8 Combining multiple DFAs into a DFAO |
|
|
54 | (1) |
|
4.9 Enumeration of paths in a DFA |
|
|
55 | (2) |
|
4.10 Formal series and linear representations |
|
|
57 | (1) |
|
|
58 | (2) |
|
|
60 | (2) |
|
|
62 | (20) |
|
5.1 Definitions and examples |
|
|
62 | (2) |
|
5.2 DFAOs for other famous sequences |
|
|
64 | (1) |
|
|
65 | (1) |
|
5.4 Cobham's little theorem |
|
|
65 | (3) |
|
|
68 | (3) |
|
5.6 Using the k-kernel to guess a DFAO for a sequence |
|
|
71 | (4) |
|
5.7 Another way to guess the automaton |
|
|
75 | (1) |
|
|
76 | (1) |
|
5.9 Fibonacci-automatic sequences |
|
|
77 | (1) |
|
5.10 Tribonacci-automatic sequences |
|
|
78 | (1) |
|
5.11 Pell-automatic sequences |
|
|
79 | (1) |
|
5.12 Ostrowski-automatic sequences |
|
|
79 | (1) |
|
5.13 Two-dimensional sequences |
|
|
80 | (2) |
|
6 First-order logic and automatic sequences |
|
|
82 | (14) |
|
|
82 | (1) |
|
6.2 Presburger arithmetic |
|
|
83 | (2) |
|
6.3 Decidability of Presburger arithmetic |
|
|
85 | (2) |
|
6.4 Extending Presburger arithmetic |
|
|
87 | (2) |
|
|
89 | (1) |
|
|
90 | (3) |
|
6.7 Other kinds of automatic sequences |
|
|
93 | (1) |
|
|
94 | (1) |
|
|
95 | (1) |
|
|
96 | (17) |
|
|
97 | (3) |
|
|
100 | (1) |
|
7.3 DFAOs included with walnut |
|
|
101 | (1) |
|
7.4 Creating DFAOs and moronisms |
|
|
102 | (2) |
|
|
104 | (1) |
|
7.6 Output of a walnut command |
|
|
104 | (1) |
|
7.7 Denning your own DFAs and DFAOs |
|
|
105 | (1) |
|
7.8 Combining two different numeration systems |
|
|
106 | (1) |
|
7.9 The correctness issue |
|
|
107 | (1) |
|
7.10 Some basic formulas in Walnut |
|
|
108 | (1) |
|
7.11 Proving summation identities with Walnut |
|
|
109 | (1) |
|
7.12 Custom numeration systems |
|
|
109 | (1) |
|
7.13 Tips for using walnut |
|
|
110 | (1) |
|
7.14 What to do if a query runs out of space |
|
|
111 | (2) |
|
8 First-order formulas for fundamental sequence properties |
|
|
113 | (80) |
|
8.1 Symbol and word occurrences |
|
|
114 | (9) |
|
8.2 Representation of integers |
|
|
123 | (1) |
|
8.3 Properties of automatic sets |
|
|
124 | (1) |
|
8.4 Periodicity, quasiperiodicity, and pseudoperiodicity |
|
|
125 | (5) |
|
8.5 Squares, cubes, and other powers |
|
|
130 | (26) |
|
8.6 Conjugates, palindromes, and borders |
|
|
156 | (12) |
|
8.7 Recurrence, uniform recurrence, linear recurrence |
|
|
168 | (2) |
|
|
170 | (12) |
|
8.9 Comparing two or more sequences |
|
|
182 | (2) |
|
8.10 Two-dimensional arrays |
|
|
184 | (2) |
|
|
186 | (5) |
|
8.12 What properties of factors can walnut check? |
|
|
191 | (2) |
|
9 Regular sequences and enumeration problems |
|
|
193 | (44) |
|
9.1 Two characterizations of k-regular sequences |
|
|
193 | (3) |
|
9.2 Examples of k-regular sequences |
|
|
196 | (2) |
|
9.3 Converting between two representations |
|
|
198 | (3) |
|
9.4 Basic properties of k-regular sequences |
|
|
201 | (3) |
|
9.5 Non-closure of the class of regular sequences |
|
|
204 | (1) |
|
9.6 K-regular sequences and k-automatic sequences |
|
|
205 | (2) |
|
9.7 Growth rate of k-regular sequences |
|
|
207 | (1) |
|
9.8 Principles of enumeration |
|
|
207 | (7) |
|
9.9 Asymptotic behavior of k-regular sequences |
|
|
214 | (2) |
|
9.10 Average values of regular sequences |
|
|
216 | (2) |
|
9.11 Enumeration examples |
|
|
218 | (18) |
|
9.12 How to guess the relations for a k-regular sequence |
|
|
236 | (1) |
|
10 Synchronized sequences |
|
|
237 | (66) |
|
10.1 Automata computing relations |
|
|
237 | (1) |
|
10.2 K-synchronized sequences |
|
|
238 | (3) |
|
10.3 Closure properties of synchronized sequences |
|
|
241 | (2) |
|
10.4 Automatic, synchronized, and regular sequences |
|
|
243 | (2) |
|
10.5 An example: the appearance function |
|
|
245 | (2) |
|
10.6 Growth rate of synchronized sequences |
|
|
247 | (4) |
|
10.7 Efficient computation of synchronized sequences |
|
|
251 | (1) |
|
10.8 Examples of synchronized functions |
|
|
252 | (23) |
|
10.9 First-order properties of synchronized sequences |
|
|
275 | (1) |
|
10.10 Synchronized sequences in two bases |
|
|
276 | (1) |
|
10.11 Fibonacci synchronization |
|
|
277 | (9) |
|
10.12 Tribonacci-synchronized sequences |
|
|
286 | (1) |
|
|
287 | (11) |
|
10.14 Unsynchronized sequences |
|
|
298 | (2) |
|
10.15 How to guess a synchronized sequence |
|
|
300 | (3) |
|
11 Additive number theory |
|
|
303 | (13) |
|
11.1 The evil and odious numbers |
|
|
304 | (2) |
|
|
306 | (2) |
|
11.3 Summands from different sets |
|
|
308 | (1) |
|
|
308 | (2) |
|
11.5 The method of over- and under-approximation |
|
|
310 | (1) |
|
|
311 | (1) |
|
|
311 | (3) |
|
11.8 Counting number of representations |
|
|
314 | (2) |
|
12 Paperfolding sequences |
|
|
316 | (11) |
|
|
316 | (3) |
|
|
319 | (1) |
|
12.3 Powers in the paperfolding sequence |
|
|
320 | (3) |
|
|
323 | (1) |
|
|
323 | (2) |
|
12.6 Rampersad's conjecture |
|
|
325 | (2) |
|
|
327 | (3) |
|
13.1 Limits to the approach |
|
|
327 | (3) |
References |
|
330 | (20) |
Index |
|
350 | |