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 | 5 |
| 3 | 15 |
| 4 | 52 |
| 5 | 201 |
| 6 | 841 |
| 7 | 3726 |
| 8 | 17213 |
| 9 | 82047 |
| 10 | 400600 |
| 11 | 1993377 |
| 12 | 10071777 |
| 13 | 51532938 |
| 14 | 266462229 |
| 15 | 1390174911 |
| 16 | 7308741084 |
| 17 | 38682855225 |
| 18 | 205940368441 |
| 19 | 1102091393574 |
| 20 | 5925177392573 |
| 21 | 31987877317887 |
| 22 | 173337754977904 |