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 | 6 |
| 5 | 1 |
| 6 | 20 |
| 7 | 1 |
| 8 | 28 |
| 9 | 84 |
| 10 | 252 |
| 11 | 1 |
| 12 | 220 |
| 13 | 1 |
| 14 | 3432 |
| 15 | 3003 |
| 16 | 120 |
| 17 | 1 |
| 18 | 816 |
| 19 | 1 |
| 20 | 15504 |
| 21 | 116280 |
| 22 | 705432 |
| 23 | 1 |
| 24 | 2024 |
| 25 | 53130 |
| 26 | 10400600 |
| 27 | 2925 |
| 28 | 1184040 |
| 29 | 1 |
| 30 | 142506 |
| 31 | 1 |
| 32 | 496 |
| 33 | 193536720 |
| 34 | 2333606220 |
| 35 | 6724520 |
| 36 | 7140 |
| 37 | 1 |
| 38 | 35345263800 |
| 39 | 8122425444 |
| 40 | 658008 |
| 41 | 1 |
| 42 | 26978328 |
| 43 | 1 |