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 | 57 |
| 3 | 364 |
| 4 | 2106 |
| 5 | 11196 |
| 6 | 55532 |
| 7 | 260720 |
| 8 | 1173240 |
| 9 | 5112544 |
| 10 | 21670160 |
| 11 | 89700624 |
| 12 | 363862092 |
| 13 | 1450606028 |
| 14 | 5697401802 |
| 15 | 22088730348 |
| 16 | 84669409935 |
| 17 | 321307769052 |
| 18 | 1208513572803 |
| 19 | 4509661963752 |
| 20 | 16709568237540 |