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 | 4 |
| 2 | 16 |
| 3 | 84 |
| 4 | 656 |
| 5 | 8148 |
| 6 | 167568 |
| 7 | 5866452 |
| 8 | 356855440 |
| 9 | 38315189204 |
| 10 | 7352635371152 |
| 11 | 2547660633170900 |
| 12 | 1607532367023451792 |
| 13 | 1860491404939092059092 |
| 14 | 3974085151281967171382928 |
| 15 | 15751822048486986712162264020 |