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 | 18 |
| 2 | 244 |
| 3 | 2952 |
| 4 | 33616 |
| 5 | 368928 |
| 6 | 3951424 |
| 7 | 41611392 |
| 8 | 432891136 |
| 9 | 4463129088 |
| 10 | 45705032704 |
| 11 | 465640261632 |
| 12 | 4725122093056 |
| 13 | 47800976744448 |
| 14 | 482407813955584 |
| 15 | 4859262511644672 |
| 16 | 48874100093157376 |
| 17 | 490992800745259008 |
| 18 | 4927942405962072064 |
| 19 | 49423539247696576512 |
| 20 | 495388313981572612096 |
| 21 | 4963106511852580896768 |