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 | 7 |
| 3 | 17 |
| 4 | 203 |
| 5 | 583 |
| 6 | 3491 |
| 7 | 10481 |
| 8 | 254963 |
| 9 | 779723 |
| 10 | 4798681 |
| 11 | 14831831 |
| 12 | 184091359 |
| 13 | 573076579 |
| 14 | 3577974043 |
| 15 | 11196388273 |
| 16 | 561766479043 |
| 17 | 1764905611763 |
| 18 | 11107979665181 |
| 19 | 35007455563451 |
| 20 | 441899444305669 |
| 21 | 1396202999849369 |