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 | 2 |
| 3 | 6 |
| 4 | 23 |
| 5 | 110 |
| 6 | 631 |
| 7 | 4218 |
| 8 | 32221 |
| 9 | 276896 |
| 10 | 2643883 |
| 11 | 27768955 |
| 12 | 318174363 |
| 13 | 3949415431 |
| 14 | 52794067318 |
| 15 | 756137263377 |
| 16 | 11551672922816 |
| 17 | 187507250145806 |
| 18 | 3222662529113641 |
| 19 | 58464560588277289 |
| 20 | 1116469710152742025 |
| 21 | 22386721651323946628 |
| 22 | 470259350616967829363 |