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 | 3 |
| 2 | 16 |
| 3 | 106 |
| 4 | 786 |
| 5 | 6244 |
| 6 | 51964 |
| 7 | 447201 |
| 8 | 3947306 |
| 9 | 35538668 |
| 10 | 325098696 |
| 11 | 3013060258 |
| 12 | 28232408848 |
| 13 | 267003169668 |
| 14 | 2545341982728 |
| 15 | 24433290332007 |
| 16 | 235967943943224 |
| 17 | 2291147902820524 |
| 18 | 22352525061549604 |
| 19 | 219006814853751540 |
| 20 | 2154083325737401740 |