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 | 6 |
| 3 | 18 |
| 4 | 50 |
| 5 | 143 |
| 6 | 397 |
| 7 | 1088 |
| 8 | 2973 |
| 9 | 8093 |
| 10 | 22014 |
| 11 | 59861 |
| 12 | 162742 |
| 13 | 442396 |
| 14 | 1202589 |
| 15 | 3268996 |
| 16 | 8886090 |
| 17 | 24154933 |
| 18 | 65659949 |
| 19 | 178482278 |
| 20 | 485165168 |
| 21 | 1318815708 |
| 22 | 3584912818 |
| 23 | 9744803414 |
| 24 | 26489122097 |
| 25 | 72004899306 |
| 26 | 195729609397 |
| 27 | 532048240570 |
| 28 | 1446257064252 |