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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 6 |
| 5 | 33 |
| 6 | 152 |
| 7 | 663 |
| 8 | 2778 |
| 9 | 11413 |
| 10 | 46332 |
| 11 | 186867 |
| 12 | 750878 |
| 13 | 3011025 |
| 14 | 12060480 |
| 15 | 48277423 |
| 16 | 193186146 |
| 17 | 772908429 |
| 18 | 3091983236 |
| 19 | 12368675691 |
| 20 | 49476275622 |
| 21 | 197908422985 |
| 22 | 791640682440 |
| 23 | 3166577409831 |
| 24 | 12666340397546 |
| 25 | 50665425902853 |
| 26 | 202661837829132 |
| 27 | 810647630936803 |