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) |
|---|---|
| 2 | 1 |
| 3 | 9 |
| 4 | 58 |
| 5 | 329 |
| 6 | 1753 |
| 7 | 9020 |
| 8 | 45442 |
| 9 | 225860 |
| 10 | 1112543 |
| 11 | 5446607 |
| 12 | 26550968 |
| 13 | 129042976 |
| 14 | 625860205 |
| 15 | 3031021096 |
| 16 | 14664729519 |
| 17 | 70906318405 |
| 18 | 342717456708 |
| 19 | 1656208470644 |
| 20 | 8003645557573 |
| 21 | 38681730323747 |
| 22 | 186985728069661 |
| 23 | 904119336235884 |