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 | 1 |
| 2 | 12 |
| 3 | 89 |
| 4 | 2681 |
| 5 | 158374 |
| 6 | 22151853 |
| 7 | 5244256701 |
| 8 | 1653293013642 |
| 9 | 584494025830394 |
| 10 | 210237300968913438 |
| 11 | 73212582945836596465 |
| 12 | 24126483152959778734211 |
| 13 | 7456837714994642537616273 |