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 | 6 |
| 2 | 36 |
| 3 | 78 |
| 4 | 282 |
| 5 | 768 |
| 6 | 2430 |
| 7 | 7086 |
| 8 | 21588 |
| 9 | 64230 |
| 10 | 193554 |
| 11 | 579264 |
| 12 | 1740054 |
| 13 | 5216502 |
| 14 | 15655428 |
| 15 | 46956702 |
| 16 | 140885610 |
| 17 | 422631744 |
| 18 | 1267935822 |
| 19 | 3803741790 |
| 20 | 11411331636 |
| 21 | 34233822966 |
| 22 | 102701747106 |
| 23 | 308104791168 |
| 24 | 924315101862 |
| 25 | 2772944127078 |