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 | 12 |
| 3 | 28 |
| 4 | 87 |
| 5 | 171 |
| 6 | 522 |
| 7 | 810 |
| 8 | 2985 |
| 9 | 2583 |
| 10 | 18528 |
| 11 | -5244 |
| 12 | 141875 |
| 13 | -241815 |
| 14 | 1393314 |
| 15 | -3905782 |
| 16 | 16326069 |
| 17 | -54884079 |
| 18 | 209607744 |
| 19 | -752322624 |
| 20 | 2812050471 |
| 21 | -10351091321 |
| 22 | 38636724474 |
| 23 | -143916146094 |
| 24 | 539225694641 |
| 25 | -2023036045635 |
| 26 | 7615213571172 |
| 27 | -28722320569796 |
| 28 | 108591659035131 |