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 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 65 |
| 7 | 257 |
| 8 | 769 |
| 9 | 21732 |
| 10 | 182268 |
| 11 | 1075171 |
| 12 | 22120299 |
| 13 | 292415838 |
| 14 | 2784944366 |
| 15 | 52394511682 |
| 16 | 914813711338 |
| 17 | 12411977351379 |
| 18 | 240868108545883 |
| 19 | 5024364548461861 |
| 20 | 88977315031536205 |
| 21 | 1888119425325238979 |
| 22 | 44744897995532996819 |
| 23 | 971263427084750362992 |