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 | 2 |
| 1 | 4 |
| 2 | 9 |
| 3 | 23 |
| 4 | 55 |
| 5 | 126 |
| 6 | 291 |
| 7 | 678 |
| 8 | 1578 |
| 9 | 3667 |
| 10 | 8523 |
| 11 | 19815 |
| 12 | 46066 |
| 13 | 107089 |
| 14 | 248950 |
| 15 | 578740 |
| 16 | 1345409 |
| 17 | 3127695 |
| 18 | 7271007 |
| 19 | 16903042 |
| 20 | 39294807 |
| 21 | 91349342 |
| 22 | 212361454 |
| 23 | 493680487 |
| 24 | 1147667895 |
| 25 | 2668004163 |
| 26 | 6202357186 |
| 27 | 14418731129 |
| 28 | 33519483178 |