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 | 25 |
| 5 | 122 |
| 6 | 727 |
| 7 | 5065 |
| 8 | 40442 |
| 9 | 363607 |
| 10 | 3633865 |
| 11 | 39957242 |
| 12 | 479365207 |
| 13 | 6230654665 |
| 14 | 87218248442 |
| 15 | 1308153733207 |
| 16 | 20929020542665 |
| 17 | 355774646344442 |
| 18 | 6403681859461207 |
| 19 | 121666029429374665 |
| 20 | 2433257782822984442 |
| 21 | 51097345853568901207 |
| 22 | 1124122393807037054665 |