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 | 3 |
| 2 | 7 |
| 3 | 18 |
| 4 | 40 |
| 5 | 88 |
| 6 | 208 |
| 7 | 513 |
| 8 | 1345 |
| 9 | 3605 |
| 10 | 9965 |
| 11 | 27984 |
| 12 | 79815 |
| 13 | 230184 |
| 14 | 669541 |
| 15 | 1961782 |
| 16 | 5781027 |
| 17 | 17121898 |
| 18 | 50926700 |
| 19 | 152037454 |
| 20 | 455379086 |
| 21 | 1367866472 |
| 22 | 4119420084 |
| 23 | 12434683582 |
| 24 | 37613680284 |
| 25 | 113995431428 |
| 26 | 346090115288 |
| 27 | 1052421037283 |
| 28 | 3205047207003 |
| 29 | 9774084239631 |