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 | 7 |
| 2 | 57 |
| 3 | 511 |
| 4 | 4817 |
| 5 | 46487 |
| 6 | 453321 |
| 7 | 4440527 |
| 8 | 43581217 |
| 9 | 428075431 |
| 10 | 4206226137 |
| 11 | 41336073247 |
| 12 | 406249753841 |
| 13 | 3992717550647 |
| 14 | 39241805801577 |
| 15 | 385683861645551 |
| 16 | 3790660025173057 |
| 17 | 37256202024955207 |
| 18 | 366169767317277561 |