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 | 0 |
| 2 | 0 |
| 3 | 22 |
| 4 | 597 |
| 5 | 7178 |
| 6 | 43090 |
| 7 | 207494 |
| 8 | 748801 |
| 9 | 2321973 |
| 10 | 6267631 |
| 11 | 15596170 |
| 12 | 34784307 |
| 13 | 74017706 |
| 14 | 147072570 |
| 15 | 277965322 |
| 16 | 503711791 |
| 17 | 884612799 |
| 18 | 1491687919 |
| 19 | 2458600175 |
| 20 | 3925566799 |
| 21 | 6133712065 |
| 22 | 9388594434 |
| 23 | 14121653942 |
| 24 | 20783339478 |
| 25 | 30178942357 |
| 26 | 43156537147 |
| 27 | 60868287839 |
| 28 | 84699183224 |
| 29 | 116688767652 |