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 | 10 |
| 2 | 70 |
| 3 | 440 |
| 4 | 2675 |
| 5 | 16106 |
| 6 | 96720 |
| 7 | 580440 |
| 8 | 3482805 |
| 9 | 20897050 |
| 10 | 125382586 |
| 11 | 752295880 |
| 12 | 4513775735 |
| 13 | 27082654970 |
| 14 | 162495930500 |
| 15 | 974975583816 |
| 16 | 5849853503865 |
| 17 | 35099121024330 |
| 18 | 210594726147310 |
| 19 | 1263568356885400 |
| 20 | 7581410141314171 |