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 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 27 |
| 5 | 69 |
| 6 | 1053 |
| 7 | 1599 |
| 8 | 2511 |
| 9 | 8167 |
| 10 | 21371 |
| 11 | 73323 |
| 12 | 225681 |
| 13 | 313401 |
| 14 | 362703 |
| 15 | 371321 |
| 16 | 1896939 |
| 17 | 2735667 |
| 18 | 3426273 |
| 19 | 3795093 |
| 20 | 5433153 |
| 21 | 302278903 |
| 22 | 1371292077 |
| 23 | 19755637749 |
| 24 | 23560349643 |
| 25 | 33184178631 |