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 | -2 |
| 2 | 3 |
| 3 | -36 |
| 4 | -155 |
| 5 | 474 |
| 6 | 1127 |
| 7 | -1992 |
| 8 | -1719 |
| 9 | -4810 |
| 10 | -31669 |
| 11 | 109332 |
| 12 | 286637 |
| 13 | -596974 |
| 14 | -904785 |
| 15 | 449136 |
| 16 | -3218287 |
| 17 | 16156782 |
| 18 | 50232979 |
| 19 | -121747380 |
| 20 | -233735691 |
| 21 | 309853258 |
| 22 | 15768823 |
| 23 | 1624290984 |
| 24 | 6853579225 |
| 25 | -19712646746 |
| 26 | -44873974053 |
| 27 | 79998871428 |
| 28 | 90434035261 |