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 | 6 |
| 3 | 21 |
| 4 | 79 |
| 5 | 309 |
| 6 | 1237 |
| 7 | 5026 |
| 8 | 20626 |
| 9 | 85242 |
| 10 | 354080 |
| 11 | 1476368 |
| 12 | 6173634 |
| 13 | 25873744 |
| 14 | 108628550 |
| 15 | 456710589 |
| 16 | 1922354351 |
| 17 | 8098984433 |
| 18 | 34147706833 |
| 19 | 144068881455 |
| 20 | 608151037123 |
| 21 | 2568318694867 |
| 22 | 10850577045131 |
| 23 | 45856273670841 |