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 | 1 |
| 4 | 2 |
| 5 | 4 |
| 6 | 31 |
| 7 | 243 |
| 8 | 3532 |
| 9 | 62810 |
| 10 | 1390718 |
| 11 | 36080361 |
| 12 | 1076477512 |
| 13 | 36281518847 |
| 14 | 1363869480379 |
| 15 | 56587508558171 |
| 16 | 2569141702825037 |
| 17 | 126714642738385906 |
| 18 | 6747643861563535720 |
| 19 | 385875940575529343271 |
| 20 | 23588199955061659841248 |
| 21 | 1535037278334227258123709 |
| 22 | 105961521687913311720698169 |