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) |
|---|---|
| 1 | 2 |
| 2 | 3 |
| 3 | 5 |
| 4 | 9 |
| 5 | 11 |
| 6 | 69 |
| 7 | 420 |
| 8 | 2361 |
| 9 | 12432 |
| 10 | 21565 |
| 11 | 28226 |
| 12 | 128389 |
| 13 | 274555 |
| 14 | 497269 |
| 15 | 836000 |
| 16 | 1151341 |
| 17 | 1973112 |
| 18 | 2202332 |
| 19 | 2458844 |
| 20 | 5402520 |