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 | 4 |
| 1 | 28 |
| 2 | 244 |
| 3 | 2188 |
| 4 | 19684 |
| 5 | 177148 |
| 6 | 1594324 |
| 7 | 14348908 |
| 8 | 129140164 |
| 9 | 1162261468 |
| 10 | 10460353204 |
| 11 | 94143178828 |
| 12 | 847288609444 |
| 13 | 7625597484988 |
| 14 | 68630377364884 |
| 15 | 617673396283948 |
| 16 | 5559060566555524 |
| 17 | 50031545098999708 |
| 18 | 450283905890997364 |
| 19 | 4052555153018976268 |
| 20 | 36472996377170786404 |