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 | 10 |
| 2 | 90 |
| 3 | 810 |
| 4 | 7210 |
| 5 | 64170 |
| 6 | 568970 |
| 7 | 5044810 |
| 8 | 44649930 |
| 9 | 395180650 |
| 10 | 3494051130 |
| 11 | 30893156970 |
| 12 | 272971707930 |
| 13 | 2411975074570 |
| 14 | 21302972395370 |
| 15 | 188151452434090 |
| 16 | 1661273238131050 |
| 17 | 14668124524584170 |
| 18 | 129481802727508250 |
| 19 | 1142991284620073450 |
| 20 | 10087904498275867530 |