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 | 1 |
| 2 | 6 |
| 3 | 55 |
| 4 | 540 |
| 5 | 5341 |
| 6 | 52866 |
| 7 | 523315 |
| 8 | 5180280 |
| 9 | 51279481 |
| 10 | 507614526 |
| 11 | 5024865775 |
| 12 | 49741043220 |
| 13 | 492385566421 |
| 14 | 4874114620986 |
| 15 | 48248760643435 |
| 16 | 477613491813360 |
| 17 | 4727886157490161 |
| 18 | 46801248083088246 |
| 19 | 463284594673392295 |
| 20 | 4586044698650834700 |
| 21 | 45397162391834954701 |