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 | 2 |
| 3 | 9 |
| 4 | 36 |
| 5 | 172 |
| 6 | 842 |
| 7 | 4310 |
| 8 | 22676 |
| 9 | 121896 |
| 10 | 666884 |
| 11 | 3699973 |
| 12 | 20771096 |
| 13 | 117765084 |
| 14 | 673367034 |
| 15 | 3878538930 |
| 16 | 22483446152 |
| 17 | 131070712924 |
| 18 | 767929882240 |
| 19 | 4519387797894 |
| 20 | 26704456819984 |
| 21 | 158367557278412 |
| 22 | 942285096541344 |
| 23 | 5623496055739052 |
| 24 | 33653373190735484 |