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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 13 |
| 4 | 36 |
| 5 | 114 |
| 6 | 495 |
| 7 | 2816 |
| 8 | 14138 |
| 9 | 64406 |
| 10 | 288079 |
| 11 | 1310914 |
| 12 | 6040052 |
| 13 | 27971466 |
| 14 | 129714539 |
| 15 | 601185145 |
| 16 | 2783395440 |
| 17 | 12878290842 |
| 18 | 59574077350 |
| 19 | 275601620452 |
| 20 | 1275129562555 |
| 21 | 5900033896489 |
| 22 | 27299793712340 |
| 23 | 126316193270001 |