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) |
|---|---|
| 1 | 3 |
| 2 | 11 |
| 3 | 49 |
| 4 | 222 |
| 5 | 1087 |
| 6 | 5604 |
| 7 | 29038 |
| 8 | 150268 |
| 9 | 764508 |
| 10 | 3857845 |
| 11 | 19929265 |
| 12 | 106104895 |
| 13 | 569770022 |
| 14 | 3029774261 |
| 15 | 15881356126 |
| 16 | 82383422858 |
| 17 | 426844152225 |
| 18 | 2236312098278 |
| 19 | 11968665825174 |
| 20 | 65501399826033 |
| 21 | 362497354225241 |
| 22 | 1992577785640176 |