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 | 3 |
| 2 | 9 |
| 3 | 30 |
| 4 | 109 |
| 5 | 418 |
| 6 | 1650 |
| 7 | 6604 |
| 8 | 26589 |
| 9 | 107274 |
| 10 | 432934 |
| 11 | 1746484 |
| 12 | 7040626 |
| 13 | 28362324 |
| 14 | 114175812 |
| 15 | 459344920 |
| 16 | 1847008989 |
| 17 | 7423262554 |
| 18 | 29822432862 |
| 19 | 119766845860 |
| 20 | 480833598054 |
| 21 | 1929896415484 |
| 22 | 7744047734652 |
| 23 | 31067665113640 |
| 24 | 124613703290994 |
| 25 | 499744683756868 |