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 | 5 |
| 1 | 18 |
| 2 | 70 |
| 3 | 299 |
| 4 | 1393 |
| 5 | 7023 |
| 6 | 38043 |
| 7 | 220054 |
| 8 | 1352082 |
| 9 | 8784991 |
| 10 | 60125371 |
| 11 | 432001747 |
| 12 | 3248914361 |
| 13 | 25508188118 |
| 14 | 208592396802 |
| 15 | 1772921926183 |
| 16 | 15632838989393 |
| 17 | 142759592985079 |
| 18 | 1348095912827295 |
| 19 | 13145321614286610 |
| 20 | 132188675368994446 |
| 21 | 1369216940917868547 |