This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 5 |
| 4 | 12 |
| 5 | 34 |
| 6 | 88 |
| 7 | 233 |
| 8 | 609 |
| 9 | 1597 |
| 10 | 4180 |
| 11 | 10946 |
| 12 | 28656 |
| 13 | 75025 |
| 14 | 196417 |
| 15 | 514229 |
| 16 | 1346268 |
| 17 | 3524578 |
| 18 | 9227464 |
| 19 | 24157817 |
| 20 | 63245985 |
| 21 | 165580141 |
| 22 | 433494436 |
| 23 | 1134903170 |
| 24 | 2971215072 |
| 25 | 7778742049 |
| 26 | 20365011073 |
| 27 | 53316291173 |
| 28 | 139583862444 |
| 29 | 365435296162 |