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 | 9 |
| 2 | 81 |
| 3 | 759 |
| 4 | 7371 |
| 5 | 73656 |
| 6 | 752913 |
| 7 | 7838298 |
| 8 | 82832706 |
| 9 | 886322710 |
| 10 | 9583986555 |
| 11 | 104568156819 |
| 12 | 1149793519368 |
| 13 | 12728471356944 |
| 14 | 141747219186705 |
| 15 | 1586867219265060 |
| 16 | 17848735288114995 |
| 17 | 201607141031660871 |
| 18 | 2285899896222757346 |
| 19 | 26008027474874327190 |
| 20 | 296840444852078282610 |
| 21 | 3397721117411729991960 |