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 | 7 |
| 3 | 47 |
| 4 | 369 |
| 5 | 3113 |
| 6 | 27631 |
| 7 | 254239 |
| 8 | 2403361 |
| 9 | 23201393 |
| 10 | 227771831 |
| 11 | 2266983119 |
| 12 | 22822484497 |
| 13 | 231994748633 |
| 14 | 2377894546783 |
| 15 | 24548520253247 |
| 16 | 255026759000897 |
| 17 | 2664111200687969 |
| 18 | 27967731861910759 |
| 19 | 294900120348032623 |
| 20 | 3121862973452544433 |
| 21 | 33167268461833410569 |