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 | 6 |
| 2 | 22 |
| 3 | 82 |
| 4 | 302 |
| 5 | 1106 |
| 6 | 4066 |
| 7 | 14902 |
| 8 | 54678 |
| 9 | 200578 |
| 10 | 735770 |
| 11 | 2699182 |
| 12 | 9901550 |
| 13 | 36323050 |
| 14 | 133247570 |
| 15 | 488805718 |
| 16 | 1793137798 |
| 17 | 6577952882 |
| 18 | 24130592458 |
| 19 | 88520767614 |
| 20 | 324729961566 |
| 21 | 1191240790586 |
| 22 | 4369952806274 |
| 23 | 16030753627238 |
| 24 | 58807285300086 |
| 25 | 215728897446594 |
| 26 | 791380812129402 |
| 27 | 2903104763095054 |