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 | 2 |
| 2 | 5 |
| 3 | 13 |
| 4 | 37 |
| 5 | 106 |
| 6 | 331 |
| 7 | 981 |
| 8 | 3473 |
| 9 | 9010 |
| 10 | 49481 |
| 11 | -7435 |
| 12 | 1744909 |
| 13 | -13392950 |
| 14 | 186659383 |
| 15 | -2369054219 |
| 16 | 33839782689 |
| 17 | -510323573086 |
| 18 | 8221794054733 |
| 19 | -140449867800547 |
| 20 | 2538204766893461 |
| 21 | -48376680944601302 |
| 22 | 969915363800997571 |
| 23 | -20407191628360339979 |