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 | 0 |
| 2 | 9 |
| 3 | 99 |
| 4 | 972 |
| 5 | 999 |
| 6 | 9900 |
| 7 | 9999 |
| 8 | 39024 |
| 9 | 60975 |
| 10 | 99999 |
| 11 | 168399 |
| 12 | 307692 |
| 13 | 467775 |
| 14 | 532224 |
| 15 | 692307 |
| 16 | 831600 |
| 17 | 972972 |
| 18 | 999999 |
| 19 | 9946224 |
| 20 | 9999999 |
| 21 | 11678832 |
| 22 | 12328767 |
| 23 | 18797427 |
| 24 | 19584972 |
| 25 | 32618124 |
| 26 | 42245775 |
| 27 | 47819475 |
| 28 | 52180524 |
| 29 | 57754224 |
| 30 | 67381875 |
| 31 | 80415027 |
| 32 | 81202572 |