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 | 2 |
| 3 | 4 |
| 4 | 11 |
| 5 | 31 |
| 6 | 110 |
| 7 | 400 |
| 8 | 1757 |
| 9 | 7861 |
| 10 | 41402 |
| 11 | 220540 |
| 12 | 1358183 |
| 13 | 8405203 |
| 14 | 59340710 |
| 15 | 418689544 |
| 16 | 3335855897 |
| 17 | 26440317193 |
| 18 | 234747589106 |
| 19 | 2065458479476 |
| 20 | 20224631361251 |
| 21 | 195625329965671 |
| 22 | 2094552876276830 |
| 23 | 22092621409440256 |