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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 5 |
| 8 | 19 |
| 9 | 61 |
| 10 | 180 |
| 11 | 498 |
| 12 | 1323 |
| 13 | 3405 |
| 14 | 8557 |
| 15 | 21103 |
| 16 | 51248 |
| 17 | 122898 |
| 18 | 291579 |
| 19 | 685562 |
| 20 | 1599209 |
| 21 | 3705122 |
| 22 | 8532309 |
| 23 | 19543867 |
| 24 | 44552066 |
| 25 | 101124867 |
| 26 | 228640542 |
| 27 | 515125815 |
| 28 | 1156829459 |
| 29 | 2590247002 |
| 30 | 5784031485 |
| 31 | 12883390590 |
| 32 | 28629914457 |