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 | 1 |
| 2 | 13 |
| 3 | 127 |
| 4 | 1469 |
| 5 | 17151 |
| 6 | 204763 |
| 7 | 2473325 |
| 8 | 30162301 |
| 9 | 370487485 |
| 10 | 4577127763 |
| 11 | 56813989827 |
| 12 | 707972099627 |
| 13 | 8851373201919 |
| 14 | 110976634957761 |
| 15 | 1394804756117877 |
| 16 | 17567994350713469 |
| 17 | 221690794842728445 |
| 18 | 2802194053806820153 |