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 | 4 |
| 3 | 9 |
| 4 | 32 |
| 5 | 71 |
| 6 | 252 |
| 7 | 559 |
| 8 | 1984 |
| 9 | 4401 |
| 10 | 15620 |
| 11 | 34649 |
| 12 | 122976 |
| 13 | 272791 |
| 14 | 968188 |
| 15 | 2147679 |
| 16 | 7622528 |
| 17 | 16908641 |
| 18 | 60012036 |
| 19 | 133121449 |
| 20 | 472473760 |
| 21 | 1048062951 |
| 22 | 3719778044 |
| 23 | 8251382159 |
| 24 | 29285750592 |
| 25 | 64962994321 |
| 26 | 230566226692 |
| 27 | 511452572409 |
| 28 | 1815244062944 |