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) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 19 |
| 5 | 49 |
| 6 | 123 |
| 7 | 297 |
| 8 | 739 |
| 9 | 1825 |
| 10 | 4491 |
| 11 | 11097 |
| 12 | 27379 |
| 13 | 67537 |
| 14 | 166683 |
| 15 | 411273 |
| 16 | 1014787 |
| 17 | 2504065 |
| 18 | 6178731 |
| 19 | 15246009 |
| 20 | 37619731 |
| 21 | 92826673 |
| 22 | 229050171 |
| 23 | 565182441 |
| 24 | 1394589475 |
| 25 | 3441155041 |
| 26 | 8491063755 |
| 27 | 20951731737 |
| 28 | 51698479411 |
| 29 | 127566197905 |
| 30 | 314770083675 |