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) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 27 |
| 6 | 81 |
| 7 | 244 |
| 8 | 739 |
| 9 | 2251 |
| 10 | 6895 |
| 11 | 21232 |
| 12 | 65703 |
| 13 | 204245 |
| 14 | 637573 |
| 15 | 1997892 |
| 16 | 6282635 |
| 17 | 19820580 |
| 18 | 62716923 |
| 19 | 198997349 |
| 20 | 633015543 |
| 21 | 2018391204 |
| 22 | 6449819095 |
| 23 | 20652628601 |
| 24 | 66256638509 |
| 25 | 212939343591 |
| 26 | 685497649231 |
| 27 | 2210217592624 |
| 28 | 7136781993563 |
| 29 | 23076554161563 |