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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 5 |
| 5 | 15 |
| 6 | 31 |
| 7 | 93 |
| 8 | 215 |
| 9 | 653 |
| 10 | 1619 |
| 11 | 4979 |
| 12 | 12949 |
| 13 | 40293 |
| 14 | 108517 |
| 15 | 341241 |
| 16 | 943937 |
| 17 | 2996127 |
| 18 | 8465319 |
| 19 | 27092419 |
| 20 | 77878271 |
| 21 | 251073791 |
| 22 | 732129719 |
| 23 | 2375764351 |
| 24 | 7012025277 |
| 25 | 22886955207 |
| 26 | 68254122669 |
| 27 | 223946197065 |
| 28 | 673885100857 |
| 29 | 2221505541773 |
| 30 | 6737598265009 |