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 | 2 |
| 3 | 12 |
| 4 | 35 |
| 5 | 117 |
| 6 | 408 |
| 7 | 1364 |
| 8 | 4617 |
| 9 | 15645 |
| 10 | 52882 |
| 11 | 178920 |
| 12 | 605331 |
| 13 | 2047705 |
| 14 | 6927424 |
| 15 | 23435384 |
| 16 | 79281057 |
| 17 | 268206185 |
| 18 | 907335090 |
| 19 | 3069491988 |
| 20 | 10384017875 |
| 21 | 35128880685 |
| 22 | 118840150776 |
| 23 | 402033352684 |
| 24 | 1360069088841 |
| 25 | 4601080767717 |
| 26 | 15565344749410 |
| 27 | 52657184101648 |
| 28 | 178137977818211 |
| 29 | 602636462317425 |