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 | 2 |
| 2 | 5 |
| 3 | 14 |
| 4 | 42 |
| 5 | 144 |
| 6 | 563 |
| 7 | 2526 |
| 8 | 12877 |
| 9 | 73778 |
| 10 | 469616 |
| 11 | 3288428 |
| 12 | 25121097 |
| 13 | 207902202 |
| 14 | 1852961189 |
| 15 | 17694468210 |
| 16 | 180234349762 |
| 17 | 1950592724756 |
| 18 | 22352145975707 |
| 19 | 270366543452702 |
| 20 | 3442413745494957 |
| 21 | 46021681757269830 |