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 | 5 |
| 2 | 17 |
| 3 | 241 |
| 4 | 1285 |
| 5 | 4385 |
| 6 | 62177 |
| 7 | 331525 |
| 8 | 1131313 |
| 9 | 16041425 |
| 10 | 85532165 |
| 11 | 291874369 |
| 12 | 4138625473 |
| 13 | 22066967045 |
| 14 | 75302455889 |
| 15 | 1067749330609 |
| 16 | 5693191965445 |
| 17 | 19427741744993 |
| 18 | 275475188671649 |
| 19 | 1468821460117765 |
| 20 | 5012282067752305 |
| 21 | 71071530927954833 |