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 | 16 |
| 4 | 93 |
| 5 | 518 |
| 6 | 2932 |
| 7 | 16709 |
| 8 | 95849 |
| 9 | 552749 |
| 10 | 3201848 |
| 11 | 18616751 |
| 12 | 108592239 |
| 13 | 635175153 |
| 14 | 3724193120 |
| 15 | 21881993115 |
| 16 | 128810517855 |
| 17 | 759515272026 |
| 18 | 4485048436792 |
| 19 | 26520334731436 |
| 20 | 157006248094198 |