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 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 26 |
| 5 | 126 |
| 6 | 745 |
| 7 | 5163 |
| 8 | 41052 |
| 9 | 367981 |
| 10 | 3669484 |
| 11 | 40282220 |
| 12 | 482650681 |
| 13 | 6267119885 |
| 14 | 87659113950 |
| 15 | 1313921407891 |
| 16 | 21010208286486 |
| 17 | 356998222642362 |
| 18 | 6423340164746737 |
| 19 | 122001442713615031 |
| 20 | 2439314857827015896 |
| 21 | 51212765334037840345 |
| 22 | 1126436834463405257528 |