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 | 10 |
| 5 | 26 |
| 6 | 75 |
| 7 | 225 |
| 8 | 711 |
| 9 | 2311 |
| 10 | 7725 |
| 11 | 26313 |
| 12 | 91141 |
| 13 | 319749 |
| 14 | 1134234 |
| 15 | 4060128 |
| 16 | 14648614 |
| 17 | 53208998 |
| 18 | 194423568 |
| 19 | 714130372 |
| 20 | 2635256408 |
| 21 | 9764995800 |
| 22 | 36320086418 |
| 23 | 135548135854 |
| 24 | 507434502474 |
| 25 | 1904982684106 |
| 26 | 7170113287574 |
| 27 | 27051804890638 |
| 28 | 102287657120454 |
| 29 | 387558371409606 |
| 30 | 1471212825012499 |
| 31 | 5594771416613721 |