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 | 5 |
| 4 | 15 |
| 5 | 52 |
| 6 | 202 |
| 7 | 859 |
| 8 | 3930 |
| 9 | 19095 |
| 10 | 97566 |
| 11 | 520257 |
| 12 | 2877834 |
| 13 | 16434105 |
| 14 | 96505490 |
| 15 | 580864901 |
| 16 | 3573876308 |
| 17 | 22426075431 |
| 18 | 143242527870 |
| 19 | 929759705415 |
| 20 | 6123822269373 |
| 21 | 40877248201308 |
| 22 | 276229252359846 |
| 23 | 1887840181793185 |
| 24 | 13037523684646810 |
| 25 | 90913254352507057 |