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 | 31 |
| 2 | 1249 |
| 3 | 2591 |
| 4 | 4801 |
| 5 | 8191 |
| 6 | 13121 |
| 7 | 76831 |
| 8 | 131071 |
| 9 | 388961 |
| 10 | 1062881 |
| 11 | 1229311 |
| 12 | 2672671 |
| 13 | 6223391 |
| 14 | 7496191 |
| 15 | 9759361 |
| 16 | 10616831 |
| 17 | 12499999 |
| 18 | 13530401 |
| 19 | 29552671 |
| 20 | 31505921 |
| 21 | 35701249 |
| 22 | 42762751 |
| 23 | 48019999 |
| 24 | 63281249 |
| 25 | 66724351 |
| 26 | 77900161 |
| 27 | 90424351 |
| 28 | 99574271 |
| 29 | 149610401 |