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 | 0 |
| 2 | 5 |
| 3 | 76 |
| 4 | 698 |
| 5 | 5088 |
| 6 | 32461 |
| 7 | 189940 |
| 8 | 1046190 |
| 9 | 5511440 |
| 10 | 28061890 |
| 11 | 139089880 |
| 12 | 674600980 |
| 13 | 3213923072 |
| 14 | 15084364221 |
| 15 | 69904629316 |
| 16 | 320443984742 |
| 17 | 1455102018480 |
| 18 | 6553035703798 |
| 19 | 29296998868904 |
| 20 | 130133568013164 |
| 21 | 574698326054848 |
| 22 | 2524813186117010 |
| 23 | 11040163152179976 |
| 24 | 48069234287414668 |
| 25 | 208481908639356448 |
| 26 | 900995206054983396 |
| 27 | 3881108155492099760 |