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 | 1 |
| 3 | 5 |
| 4 | 11 |
| 5 | 59 |
| 6 | 439 |
| 7 | 2659 |
| 8 | 13705 |
| 9 | 160649 |
| 10 | 2009681 |
| 11 | 16966421 |
| 12 | 183312931 |
| 13 | 2078169235 |
| 14 | 34203787591 |
| 15 | 657685416179 |
| 16 | 8054585463569 |
| 17 | 104530824746129 |
| 18 | 2595754682459425 |
| 19 | 39767021562661669 |
| 20 | 758079429084897211 |