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 | 1 |
| 2 | 3 |
| 3 | 5 |
| 4 | 13 |
| 5 | 52 |
| 6 | 123 |
| 7 | 366 |
| 8 | 909 |
| 9 | 2444 |
| 10 | 7108 |
| 11 | 19157 |
| 12 | 53957 |
| 13 | 146826 |
| 14 | 400704 |
| 15 | 1115852 |
| 16 | 3059907 |
| 17 | 8475420 |
| 18 | 23369304 |
| 19 | 64225984 |
| 20 | 177572352 |
| 21 | 488839323 |
| 22 | 1349102071 |
| 23 | 3722419367 |
| 24 | 10255126169 |
| 25 | 28303059509 |
| 26 | 78013005366 |
| 27 | 215160477217 |
| 28 | 593488173404 |
| 29 | 1636220978049 |