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 | 4 |
| 3 | 11 |
| 4 | 40 |
| 5 | 172 |
| 6 | 820 |
| 7 | 4227 |
| 8 | 23336 |
| 9 | 137282 |
| 10 | 857178 |
| 11 | 5659496 |
| 12 | 39372213 |
| 13 | 287657495 |
| 14 | 2200586044 |
| 15 | 17579891124 |
| 16 | 146309132849 |
| 17 | 1265828289411 |
| 18 | 11362930635404 |