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 | 1 |
| 3 | 4 |
| 4 | 9 |
| 5 | 100 |
| 6 | 121 |
| 7 | 676 |
| 8 | 900 |
| 9 | 10000 |
| 10 | 12100 |
| 11 | 12321 |
| 12 | 90000 |
| 13 | 1000000 |
| 14 | 1210000 |
| 15 | 1232100 |
| 16 | 1234321 |
| 17 | 9000000 |
| 18 | 100000000 |
| 19 | 121000000 |
| 20 | 123210000 |
| 21 | 123432100 |
| 22 | 123454321 |
| 23 | 900000000 |
| 24 | 10000000000 |
| 25 | 11122233444 |
| 26 | 12100000000 |
| 27 | 12321000000 |
| 28 | 12343210000 |