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 | 2 |
| 2 | 3 |
| 3 | 12 |
| 4 | 53 |
| 5 | 222 |
| 6 | 899 |
| 7 | 3540 |
| 8 | 13657 |
| 9 | 51882 |
| 10 | 194727 |
| 11 | 723760 |
| 12 | 2668453 |
| 13 | 9771870 |
| 14 | 35577935 |
| 15 | 128887616 |
| 16 | 464885073 |
| 17 | 1670362418 |
| 18 | 5981289455 |
| 19 | 21352860808 |
| 20 | 76020123293 |
| 21 | 269977176422 |
| 22 | 956644165503 |
| 23 | 3382864303648 |
| 24 | 11940005836537 |