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 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 13 |
| 5 | 148 |
| 6 | 4530 |
| 7 | 266614 |
| 8 | 31451264 |
| 9 | 7366255436 |
| 10 | 3449652145180 |
| 11 | 3240150686268514 |
| 12 | 6112883022923529310 |
| 13 | 23174784819204929919428 |
| 14 | 176546343645071836902594288 |
| 15 | 2701845395848698682311893154024 |
| 16 | 83036184895986451215378727412638816 |
| 17 | 5122922885438069578928905234650082410736 |