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 | 1 |
| 2 | 0 |
| 3 | 21 |
| 4 | 31 |
| 5 | 266 |
| 6 | 672 |
| 7 | 3484 |
| 8 | 11375 |
| 9 | 48768 |
| 10 | 177023 |
| 11 | 716418 |
| 12 | 2730315 |
| 13 | 10878520 |
| 14 | 42485638 |
| 15 | 169181010 |
| 16 | 670042125 |
| 17 | 2678678730 |
| 18 | 10705526976 |
| 19 | 43007270292 |
| 20 | 173003915322 |
| 21 | 698235680844 |
| 22 | 2822901487191 |
| 23 | 11439823946306 |
| 24 | 46438021798875 |
| 25 | 188856966693230 |
| 26 | 769224288476860 |
| 27 | 3137871076604544 |
| 28 | 12817404260955810 |