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 | 8 |
| 4 | 26 |
| 5 | 70 |
| 6 | 820 |
| 7 | 5152 |
| 8 | 20316 |
| 9 | 388712 |
| 10 | 3666188 |
| 11 | 17298908 |
| 12 | 501805832 |
| 13 | 6256792412 |
| 14 | 33844737292 |
| 15 | 1353617016078 |
| 16 | 20960708128068 |
| 17 | 137741948419428 |
| 18 | 6588092586831028 |
| 19 | 121860622573650906 |
| 20 | 924837580461274556 |