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 | 11 |
| 3 | 71 |
| 4 | 431 |
| 5 | 2591 |
| 6 | 15551 |
| 7 | 93311 |
| 8 | 559871 |
| 9 | 3359231 |
| 10 | 20155391 |
| 11 | 120932351 |
| 12 | 725594111 |
| 13 | 4353564671 |
| 14 | 26121388031 |
| 15 | 156728328191 |
| 16 | 940369969151 |
| 17 | 5642219814911 |
| 18 | 33853318889471 |
| 19 | 203119913336831 |
| 20 | 1218719480020991 |
| 21 | 7312316880125951 |
| 22 | 43873901280755711 |
| 23 | 263243407684534271 |