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 | 13 |
| 3 | 41 |
| 4 | 105 |
| 5 | 247 |
| 6 | 581 |
| 7 | 1437 |
| 8 | 3793 |
| 9 | 10571 |
| 10 | 30525 |
| 11 | 89905 |
| 12 | 267449 |
| 13 | 799359 |
| 14 | 2394229 |
| 15 | 7177829 |
| 16 | 21527457 |
| 17 | 64574995 |
| 18 | 193716077 |
| 19 | 581137593 |
| 20 | 1743400201 |
| 21 | 5230185863 |
| 22 | 15690540453 |
| 23 | 47071601581 |
| 24 | 141214782065 |
| 25 | 423644320347 |
| 26 | 1270932931741 |
| 27 | 3812798762177 |
| 28 | 11438396249433 |
| 29 | 34315188706831 |