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 | -3 |
| 2 | 6 |
| 3 | -12 |
| 4 | 24 |
| 5 | -45 |
| 6 | 78 |
| 7 | -132 |
| 8 | 222 |
| 9 | -363 |
| 10 | 576 |
| 11 | -900 |
| 12 | 1392 |
| 13 | -2121 |
| 14 | 3180 |
| 15 | -4716 |
| 16 | 6936 |
| 17 | -10098 |
| 18 | 14550 |
| 19 | -20796 |
| 20 | 29520 |
| 21 | -41595 |
| 22 | 58176 |
| 23 | -80856 |
| 24 | 111750 |
| 25 | -153561 |
| 26 | 209820 |
| 27 | -285240 |
| 28 | 385968 |
| 29 | -519840 |
| 30 | 696960 |
| 31 | -930516 |
| 32 | 1237470 |
| 33 | -1639314 |
| 34 | 2163456 |
| 35 | -2845080 |
| 36 | 3728904 |
| 37 | -4871211 |