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 | 0 |
| 1 | 2 |
| 2 | 10 |
| 3 | 36 |
| 4 | 114 |
| 5 | 332 |
| 6 | 916 |
| 7 | 2428 |
| 8 | 6242 |
| 9 | 15652 |
| 10 | 38460 |
| 11 | 92916 |
| 12 | 221256 |
| 13 | 520332 |
| 14 | 1210448 |
| 15 | 2789100 |
| 16 | 6372498 |
| 17 | 14450420 |
| 18 | 32547188 |
| 19 | 72861376 |
| 20 | 162211196 |
| 21 | 359318644 |
| 22 | 792287340 |
| 23 | 1739623672 |
| 24 | 3804904316 |
| 25 | 8292351960 |
| 26 | 18012452664 |
| 27 | 39006099616 |
| 28 | 84226667004 |
| 29 | 181387693028 |
| 30 | 389657293304 |