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 | 19 |
| 2 | 209 |
| 3 | 1710 |
| 4 | 11495 |
| 5 | 66880 |
| 6 | 347681 |
| 7 | 1649637 |
| 8 | 7252300 |
| 9 | 29875505 |
| 10 | 116319938 |
| 11 | 430976031 |
| 12 | 1527928814 |
| 13 | 5206792965 |
| 14 | 17119704425 |
| 15 | 54484060983 |
| 16 | 168297474675 |
| 17 | 505762373795 |
| 18 | 1481733152790 |
| 19 | 4239676354650 |
| 20 | 11866652524496 |
| 21 | 32536693623850 |