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 | 2 |
| 2 | 6 |
| 3 | 12 |
| 4 | 44 |
| 5 | 88 |
| 6 | 264 |
| 7 | 528 |
| 8 | 2064 |
| 9 | 4128 |
| 10 | 12384 |
| 11 | 24768 |
| 12 | 90816 |
| 13 | 181632 |
| 14 | 544896 |
| 15 | 1089792 |
| 16 | 4292864 |
| 17 | 8585728 |
| 18 | 25757184 |
| 19 | 51514368 |
| 20 | 188886016 |
| 21 | 377772032 |
| 22 | 1133316096 |
| 23 | 2266632192 |
| 24 | 8860471296 |
| 25 | 17720942592 |
| 26 | 53162827776 |
| 27 | 106325655552 |
| 28 | 389860737024 |
| 29 | 779721474048 |
| 30 | 2339164422144 |