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 | 8 |
| 3 | 21 |
| 4 | 60 |
| 5 | 197 |
| 6 | 756 |
| 7 | 3367 |
| 8 | 17136 |
| 9 | 98153 |
| 10 | 624804 |
| 11 | 4375283 |
| 12 | 33424512 |
| 13 | 276622829 |
| 14 | 2465449252 |
| 15 | 23543304919 |
| 16 | 239810132288 |
| 17 | 2595353815825 |
| 18 | 29740563986500 |
| 19 | 359735190398875 |
| 20 | 4580290700420064 |
| 21 | 61233976084442741 |