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 | 3 |
| 2 | 7 |
| 3 | 31 |
| 4 | 127 |
| 5 | 8191 |
| 6 | 173 |
| 7 | 131071 |
| 8 | 524287 |
| 9 | 2147483647 |
| 10 | 699053 |
| 11 | 3313 |
| 12 | 13271393 |
| 13 | 2305843009213693951 |
| 14 | 209659 |
| 15 | 9361975431089 |
| 16 | 10670593 |
| 17 | 618970019642690137449562111 |
| 18 | 18861569 |
| 19 | 23253381919 |
| 20 | 162259276829213363391578010288127 |
| 21 | 177722254122587407 |
| 22 | 170141183460469231731687303715884105727 |