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 | 1 |
| 1 | 9 |
| 2 | 37 |
| 3 | 157 |
| 4 | 665 |
| 5 | 2817 |
| 6 | 11933 |
| 7 | 50549 |
| 8 | 214129 |
| 9 | 907065 |
| 10 | 3842389 |
| 11 | 16276621 |
| 12 | 68948873 |
| 13 | 292072113 |
| 14 | 1237237325 |
| 15 | 5241021413 |
| 16 | 22201322977 |
| 17 | 94046313321 |
| 18 | 398386576261 |
| 19 | 1687592618365 |
| 20 | 7148757049721 |
| 21 | 30282620817249 |
| 22 | 128279240318717 |
| 23 | 543399582092117 |
| 24 | 2301877568687185 |