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 | 2 |
| 2 | 8 |
| 3 | 39 |
| 4 | 214 |
| 5 | 1274 |
| 6 | 8028 |
| 7 | 52698 |
| 8 | 356630 |
| 9 | 2470848 |
| 10 | 17440690 |
| 11 | 124981126 |
| 12 | 906887612 |
| 13 | 6650054278 |
| 14 | 49202240010 |
| 15 | 366856871768 |
| 16 | 2753772204894 |
| 17 | 20793368929970 |
| 18 | 157831516488476 |
| 19 | 1203618076715682 |
| 20 | 9217256564429454 |
| 21 | 70852472349915280 |