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 | 13 |
| 2 | 91 |
| 3 | 468 |
| 4 | 1989 |
| 5 | 7384 |
| 6 | 24739 |
| 7 | 76427 |
| 8 | 220948 |
| 9 | 604175 |
| 10 | 1575392 |
| 11 | 3941847 |
| 12 | 9511944 |
| 13 | 22226049 |
| 14 | 50458447 |
| 15 | 111609537 |
| 16 | 241099027 |
| 17 | 509680951 |
| 18 | 1056262792 |
| 19 | 2149214288 |
| 20 | 4299359012 |
| 21 | 8465605408 |
| 22 | 16424772637 |
| 23 | 31429372312 |
| 24 | 59365381608 |
| 25 | 110770031489 |
| 26 | 204315725953 |
| 27 | 372772306309 |
| 28 | 673125106316 |