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 | 6 |
| 3 | 13 |
| 4 | 30 |
| 5 | 74 |
| 6 | 196 |
| 7 | 557 |
| 8 | 1686 |
| 9 | 5374 |
| 10 | 17820 |
| 11 | 60834 |
| 12 | 212108 |
| 13 | 751092 |
| 14 | 2690824 |
| 15 | 9727613 |
| 16 | 35423206 |
| 17 | 129775862 |
| 18 | 477900844 |
| 19 | 1767787478 |
| 20 | 6565168996 |
| 21 | 24468364172 |
| 22 | 91486757944 |
| 23 | 343068002258 |
| 24 | 1289920924540 |
| 25 | 4861979955884 |