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 | 3 |
| 4 | 12 |
| 5 | 63 |
| 6 | 396 |
| 7 | 2926 |
| 8 | 24497 |
| 9 | 229757 |
| 10 | 2377153 |
| 11 | 26917186 |
| 12 | 330804783 |
| 13 | 4387399275 |
| 14 | 62455948949 |
| 15 | 950123048257 |
| 16 | 15384516283921 |
| 17 | 264229711285878 |
| 18 | 4798448004296966 |
| 19 | 91878671010619078 |
| 20 | 1850134691327469413 |
| 21 | 39088537892778891963 |
| 22 | 864610314507158356377 |