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 | 13 |
| 2 | 85 |
| 3 | 517 |
| 4 | 3109 |
| 5 | 18661 |
| 6 | 111973 |
| 7 | 671845 |
| 8 | 4031077 |
| 9 | 24186469 |
| 10 | 145118821 |
| 11 | 870712933 |
| 12 | 5224277605 |
| 13 | 31345665637 |
| 14 | 188073993829 |
| 15 | 1128443962981 |
| 16 | 6770663777893 |
| 17 | 40623982667365 |
| 18 | 243743896004197 |
| 19 | 1462463376025189 |
| 20 | 8774780256151141 |
| 21 | 52648681536906853 |