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 | 5 |
| 3 | 16 |
| 4 | 62 |
| 5 | 276 |
| 6 | 1377 |
| 7 | 7596 |
| 8 | 45789 |
| 9 | 298626 |
| 10 | 2090910 |
| 11 | 15621640 |
| 12 | 123897413 |
| 13 | 1038535174 |
| 14 | 9165475893 |
| 15 | 84886111212 |
| 16 | 822648571314 |
| 17 | 8321077557124 |
| 18 | 87648445601429 |
| 19 | 959450073912136 |
| 20 | 10894692556576613 |
| 21 | 128114221270929646 |