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 | 12 |
| 2 | 144 |
| 3 | 636 |
| 4 | 2709 |
| 5 | 13132 |
| 6 | 54684 |
| 7 | 210118 |
| 8 | 818892 |
| 9 | 3093184 |
| 10 | 11234900 |
| 11 | 40417797 |
| 12 | 143649720 |
| 13 | 501215991 |
| 14 | 1730494710 |
| 15 | 5926924410 |
| 16 | 20097642000 |
| 17 | 67608559928 |
| 18 | 226048464005 |
| 19 | 751020224850 |
| 20 | 2480966742240 |
| 21 | 8157248135323 |
| 22 | 26701216937370 |