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 | 4 |
| 3 | 5 |
| 4 | 9 |
| 5 | 23 |
| 6 | 147 |
| 7 | 317 |
| 8 | 464 |
| 9 | 781 |
| 10 | 2807 |
| 11 | 3588 |
| 12 | 45863 |
| 13 | 49451 |
| 14 | 194216 |
| 15 | 243667 |
| 16 | 437883 |
| 17 | 1119433 |
| 18 | 7154481 |
| 19 | 15428395 |
| 20 | 22582876 |
| 21 | 38011271 |
| 22 | 136616689 |
| 23 | 174627960 |
| 24 | 2232152209 |
| 25 | 2406780169 |
| 26 | 9452492716 |
| 27 | 11859272885 |