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 | 30 |
| 1 | -180 |
| 2 | 630 |
| 3 | -1680 |
| 4 | 3780 |
| 5 | -7560 |
| 6 | 13860 |
| 7 | -23760 |
| 8 | 38610 |
| 9 | -60060 |
| 10 | 90090 |
| 11 | -131040 |
| 12 | 185640 |
| 13 | -257040 |
| 14 | 348840 |
| 15 | -465120 |
| 16 | 610470 |
| 17 | -790020 |
| 18 | 1009470 |
| 19 | -1275120 |
| 20 | 1593900 |
| 21 | -1973400 |
| 22 | 2421900 |
| 23 | -2948400 |
| 24 | 3562650 |
| 25 | -4275180 |
| 26 | 5097330 |
| 27 | -6041280 |
| 28 | 7120080 |
| 29 | -8347680 |
| 30 | 9738960 |