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 | 1 |
| 6 | 1 |
| 7 | 5 |
| 8 | 11 |
| 9 | 49 |
| 10 | 123 |
| 11 | 521 |
| 12 | 1583 |
| 13 | 6581 |
| 14 | 23239 |
| 15 | 95509 |
| 16 | 384771 |
| 17 | 1570265 |
| 18 | 7106995 |
| 19 | 28869825 |
| 20 | 145034327 |
| 21 | 587270877 |
| 22 | 3242792607 |
| 23 | 13100475021 |
| 24 | 78866628011 |
| 25 | 318067071169 |
| 26 | 2073381189259 |
| 27 | 8350998470777 |
| 28 | 58602568320255 |
| 29 | 235794888434053 |
| 30 | 1772311322357623 |