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 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 23 |
| 6 | 60 |
| 7 | 152 |
| 8 | 388 |
| 9 | 984 |
| 10 | 2501 |
| 11 | 6347 |
| 12 | 16117 |
| 13 | 40911 |
| 14 | 103864 |
| 15 | 263664 |
| 16 | 669352 |
| 17 | 1699216 |
| 18 | 4313673 |
| 19 | 10950739 |
| 20 | 27799745 |
| 21 | 70572839 |
| 22 | 179157364 |
| 23 | 454811656 |
| 24 | 1154592108 |
| 25 | 2931065640 |
| 26 | 7440849549 |
| 27 | 18889457819 |
| 28 | 47953075565 |