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 | 45 |
| 3 | 291 |
| 4 | 2033 |
| 5 | 10327 |
| 6 | 55901 |
| 7 | 377971 |
| 8 | 2580161 |
| 9 | 13329991 |
| 10 | 68092909 |
| 11 | 475337827 |
| 12 | 3047910961 |
| 13 | 21335374615 |
| 14 | 108342024605 |
| 15 | 611555770419 |
| 16 | 4227169747201 |
| 17 | 22855656310535 |
| 18 | 114836769975597 |
| 19 | 592467546841635 |
| 20 | 4147130288467697 |
| 21 | 24449879086004055 |
| 22 | 171122765320764253 |