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 | 3 |
| 2 | 10 |
| 3 | 33 |
| 4 | 105 |
| 5 | 324 |
| 6 | 977 |
| 7 | 2895 |
| 8 | 8462 |
| 9 | 24465 |
| 10 | 70101 |
| 11 | 199368 |
| 12 | 563425 |
| 13 | 1583643 |
| 14 | 4430290 |
| 15 | 12342849 |
| 16 | 34262337 |
| 17 | 94800780 |
| 18 | 261545777 |
| 19 | 719697255 |
| 20 | 1975722326 |
| 21 | 5412138033 |
| 22 | 14796520365 |
| 23 | 40380240528 |
| 24 | 110016825025 |
| 25 | 299285288499 |
| 26 | 813011578522 |
| 27 | 2205652007265 |
| 28 | 5976479585817 |