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 | 42 |
| 2 | -2268 |
| 3 | 395304 |
| 4 | -64600914 |
| 5 | 11644170552 |
| 6 | -2188350306072 |
| 7 | 424652412357696 |
| 8 | -84326944950450972 |
| 9 | 17044476557469661986 |
| 10 | -3493525880987663047128 |
| 11 | 724189608821718233434296 |
| 12 | -151528575864988356484968840 |
| 13 | 31955212589107172812017247992 |