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 | 7 |
| 2 | 56 |
| 3 | 455 |
| 4 | 3640 |
| 5 | 29127 |
| 6 | 233016 |
| 7 | 1864135 |
| 8 | 14913080 |
| 9 | 119304647 |
| 10 | 954437176 |
| 11 | 7635497415 |
| 12 | 61083979320 |
| 13 | 488671834567 |
| 14 | 3909374676536 |
| 15 | 31274997412295 |
| 16 | 250199979298360 |
| 17 | 2001599834386887 |
| 18 | 16012798675095096 |
| 19 | 128102389400760775 |