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 | 8 |
| 3 | 35 |
| 4 | 115 |
| 5 | 429 |
| 6 | 1425 |
| 7 | 4803 |
| 8 | 15398 |
| 9 | 48940 |
| 10 | 151046 |
| 11 | 459000 |
| 12 | 1373219 |
| 13 | 4037721 |
| 14 | 11723911 |
| 15 | 33566828 |
| 16 | 94993571 |
| 17 | 265722551 |
| 18 | 735543433 |
| 19 | 2015558930 |
| 20 | 5471271099 |
| 21 | 14719853084 |
| 22 | 39266487114 |
| 23 | 103908002173 |
| 24 | 272855152096 |
| 25 | 711272144097 |
| 26 | 1841162650896 |
| 27 | 4734074846631 |