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 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 17 |
| 5 | 43 |
| 6 | 114 |
| 7 | 308 |
| 8 | 837 |
| 9 | 2294 |
| 10 | 6330 |
| 11 | 17603 |
| 12 | 49255 |
| 13 | 138359 |
| 14 | 390374 |
| 15 | 1105655 |
| 16 | 3142141 |
| 17 | 8956264 |
| 18 | 25592485 |
| 19 | 73305487 |
| 20 | 210435337 |
| 21 | 605304274 |
| 22 | 1744271476 |
| 23 | 5034584633 |
| 24 | 14553714389 |
| 25 | 42129545594 |
| 26 | 122112130949 |
| 27 | 354362929036 |