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 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 3 |
| 5 | 9 |
| 6 | 9 |
| 7 | 29 |
| 8 | 29 |
| 9 | 99 |
| 10 | 99 |
| 11 | 351 |
| 12 | 351 |
| 13 | 1275 |
| 14 | 1275 |
| 15 | 4707 |
| 16 | 4707 |
| 17 | 17577 |
| 18 | 17577 |
| 19 | 66197 |
| 20 | 66197 |
| 21 | 250953 |
| 22 | 250953 |
| 23 | 956385 |
| 24 | 956385 |
| 25 | 3660541 |
| 26 | 3660541 |
| 27 | 14061141 |
| 28 | 14061141 |
| 29 | 54177741 |
| 30 | 54177741 |
| 31 | 209295261 |
| 32 | 209295261 |
| 33 | 810375651 |
| 34 | 810375651 |