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 | 2 |
| 2 | 7 |
| 3 | 29 |
| 4 | 121 |
| 5 | 497 |
| 6 | 2017 |
| 7 | 8129 |
| 8 | 32641 |
| 9 | 130817 |
| 10 | 523777 |
| 11 | 2096129 |
| 12 | 8386561 |
| 13 | 33550337 |
| 14 | 134209537 |
| 15 | 536854529 |
| 16 | 2147450881 |
| 17 | 8589869057 |
| 18 | 34359607297 |
| 19 | 137438691329 |
| 20 | 549755289601 |
| 21 | 2199022206977 |
| 22 | 8796090925057 |
| 23 | 35184367894529 |