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 | 0 |
| 2 | 3 |
| 3 | -1 |
| 4 | 8 |
| 5 | -6 |
| 6 | 22 |
| 7 | -25 |
| 8 | 64 |
| 9 | -91 |
| 10 | 195 |
| 11 | -312 |
| 12 | 612 |
| 13 | -1040 |
| 14 | 1953 |
| 15 | -3420 |
| 16 | 6287 |
| 17 | -11173 |
| 18 | 20328 |
| 19 | -36386 |
| 20 | 65870 |
| 21 | -118313 |
| 22 | 213668 |
| 23 | -384423 |
| 24 | 693447 |
| 25 | -1248624 |
| 26 | 2251096 |
| 27 | -4054896 |
| 28 | 7308465 |
| 29 | -13167160 |
| 30 | 23729195 |
| 31 | -42755049 |
| 32 | 77046280 |
| 33 | -138827182 |
| 34 | 250164694 |
| 35 | -450772777 |
| 36 | 812274984 |
| 37 | -1463655843 |