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 | 5 |
| 3 | 31 |
| 4 | 222 |
| 5 | 1727 |
| 6 | 14179 |
| 7 | 120930 |
| 8 | 1060992 |
| 9 | 9514463 |
| 10 | 86818391 |
| 11 | 803516167 |
| 12 | 7524700644 |
| 13 | 71169939341 |
| 14 | 678877680077 |
| 15 | 6523424076116 |
| 16 | 63087757216084 |
| 17 | 613575943566436 |
| 18 | 5997490784042496 |
| 19 | 58886692596764215 |
| 20 | 580516324380845804 |
| 21 | 5743718741275361697 |
| 22 | 57017511243375535969 |