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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | -3 |
| 4 | -20 |
| 5 | -19 |
| 6 | 102 |
| 7 | 337 |
| 8 | -40 |
| 9 | -2439 |
| 10 | -4598 |
| 11 | 7877 |
| 12 | 47940 |
| 13 | 40741 |
| 14 | -254098 |
| 15 | -793383 |
| 16 | 191920 |
| 17 | 5937521 |
| 18 | 10531602 |
| 19 | -20499443 |
| 20 | -114720100 |
| 21 | -85944099 |
| 22 | 631152502 |
| 23 | 1863913697 |
| 24 | -690240120 |
| 25 | -14427876119 |
| 26 | -24024071398 |
| 27 | 52946990037 |
| 28 | 274062479860 |
| 29 | 177496029461 |