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 | 21 |
| 2 | 131 |
| 3 | 471 |
| 4 | 1251 |
| 5 | 2751 |
| 6 | 5321 |
| 7 | 9381 |
| 8 | 15421 |
| 9 | 24001 |
| 10 | 35751 |
| 11 | 51371 |
| 12 | 71631 |
| 13 | 97371 |
| 14 | 129501 |
| 15 | 169001 |
| 16 | 216921 |
| 17 | 274381 |
| 18 | 342571 |
| 19 | 422751 |
| 20 | 516251 |
| 21 | 624471 |
| 22 | 748881 |
| 23 | 891021 |
| 24 | 1052501 |
| 25 | 1235001 |
| 26 | 1440271 |