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 | 8 |
| 2 | 21 |
| 3 | 153 |
| 4 | 865 |
| 5 | 4665 |
| 6 | 25556 |
| 7 | 144847 |
| 8 | 817539 |
| 9 | 4574717 |
| 10 | 25577718 |
| 11 | 143371820 |
| 12 | 804082832 |
| 13 | 4506873305 |
| 14 | 25254564785 |
| 15 | 141534685147 |
| 16 | 793277267583 |
| 17 | 4446076119277 |
| 18 | 24918173471356 |
| 19 | 139655004825056 |
| 20 | 782709245520654 |