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 | 2 |
| 2 | 3 |
| 3 | 10 |
| 4 | 28 |
| 5 | 198 |
| 6 | 520 |
| 7 | 3570 |
| 8 | 9348 |
| 9 | 64078 |
| 10 | 1149850 |
| 11 | 3010348 |
| 12 | 54018520 |
| 13 | 370248450 |
| 14 | 969323028 |
| 15 | 6643838878 |
| 16 | 119218851370 |
| 17 | 2139295485798 |
| 18 | 5600748293800 |
| 19 | 100501350283428 |
| 20 | 688846502588398 |
| 21 | 1803423556807920 |
| 22 | 32361122672259148 |