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 | 6 |
| 2 | 68 |
| 3 | 442 |
| 4 | 2218 |
| 5 | 9528 |
| 6 | 36834 |
| 7 | 131856 |
| 8 | 445000 |
| 9 | 1433294 |
| 10 | 4444006 |
| 11 | 13349510 |
| 12 | 39041224 |
| 13 | 111583236 |
| 14 | 312618368 |
| 15 | 860662498 |
| 16 | 2333112020 |
| 17 | 6238124024 |
| 18 | 16474149036 |
| 19 | 43023953304 |
| 20 | 111230237224 |
| 21 | 284926172100 |
| 22 | 723731637254 |