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 | 1 |
| 2 | 2 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 13 |
| 7 | 83 |
| 8 | 513 |
| 9 | 4052 |
| 10 | 41197 |
| 11 | 462069 |
| 12 | 5597201 |
| 13 | 76094134 |
| 14 | 1153902701 |
| 15 | 18981358311 |
| 16 | 336018968449 |
| 17 | 6413439874792 |
| 18 | 131386321421901 |
| 19 | 2867812411156521 |
| 20 | 66426533670738769 |
| 21 | 1629082910078009770 |
| 22 | 42175861619149917325 |
| 23 | 1148999152027728530363 |
| 24 | 32856688248674995989889 |