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 | 9 |
| 3 | 49 |
| 4 | 51 |
| 5 | 99 |
| 6 | 249 |
| 7 | 251 |
| 8 | 499 |
| 9 | 501 |
| 10 | 749 |
| 11 | 751 |
| 12 | 999 |
| 13 | 1249 |
| 14 | 3751 |
| 15 | 4999 |
| 16 | 5001 |
| 17 | 6249 |
| 18 | 8751 |
| 19 | 9999 |
| 20 | 18751 |
| 21 | 31249 |
| 22 | 49999 |
| 23 | 50001 |
| 24 | 68751 |
| 25 | 81249 |
| 26 | 99999 |
| 27 | 218751 |
| 28 | 281249 |
| 29 | 499999 |
| 30 | 500001 |
| 31 | 718751 |
| 32 | 781249 |
| 33 | 999999 |
| 34 | 4218751 |
| 35 | 4999999 |
| 36 | 5000001 |
| 37 | 5781249 |
| 38 | 9218751 |