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 | 1 |
| 2 | 6 |
| 3 | 25 |
| 4 | 98 |
| 5 | 378 |
| 6 | 1452 |
| 7 | 5577 |
| 8 | 21450 |
| 9 | 82654 |
| 10 | 319124 |
| 11 | 1234506 |
| 12 | 4784276 |
| 13 | 18572500 |
| 14 | 72209880 |
| 15 | 281150505 |
| 16 | 1096087770 |
| 17 | 4278278070 |
| 18 | 16717354500 |
| 19 | 65388738030 |
| 20 | 256000696380 |
| 21 | 1003116947820 |
| 22 | 3933750236520 |
| 23 | 15437682614250 |
| 24 | 60625494924228 |
| 25 | 238235373671148 |
| 26 | 936735006679752 |