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 | 9 |
| 3 | 12 |
| 4 | 23 |
| 5 | 62 |
| 6 | 122 |
| 7 | 305 |
| 8 | 793 |
| 9 | 1757 |
| 10 | 4500 |
| 11 | 11625 |
| 12 | 27164 |
| 13 | 68288 |
| 14 | 174229 |
| 15 | 418787 |
| 16 | 1042345 |
| 17 | 2631836 |
| 18 | 6422387 |
| 19 | 15922406 |
| 20 | 39917606 |
| 21 | 98193097 |
| 22 | 243159537 |
| 23 | 606853585 |
| 24 | 1499009192 |
| 25 | 3711839149 |
| 26 | 9238182444 |
| 27 | 22867354964 |
| 28 | 56640304965 |
| 29 | 140740151139 |