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 | 14 |
| 4 | 114 |
| 5 | 1131 |
| 6 | 12393 |
| 7 | 146712 |
| 8 | 1838094 |
| 9 | 24088842 |
| 10 | 327526513 |
| 11 | 4593918125 |
| 12 | 66198455671 |
| 13 | 977113573208 |
| 14 | 14741071612583 |
| 15 | 226941948201964 |
| 16 | 3561383719180100 |
| 17 | 56926946565867437 |
| 18 | 926444637518092848 |
| 19 | 15347533201937448776 |
| 20 | 258809102457332568964 |