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 | 0 |
| 1 | 1 |
| 2 | 0 |
| 3 | 3 |
| 4 | 4 |
| 5 | 15 |
| 6 | 36 |
| 7 | 105 |
| 8 | 288 |
| 9 | 819 |
| 10 | 2320 |
| 11 | 6633 |
| 12 | 19020 |
| 13 | 54769 |
| 14 | 158172 |
| 15 | 458055 |
| 16 | 1329552 |
| 17 | 3867075 |
| 18 | 11267856 |
| 19 | 32884953 |
| 20 | 96111900 |
| 21 | 281267469 |
| 22 | 824083260 |
| 23 | 2417052267 |
| 24 | 7096175856 |
| 25 | 20852160525 |
| 26 | 61324675776 |
| 27 | 180488550375 |
| 28 | 531581605828 |
| 29 | 1566658748079 |
| 30 | 4620016882740 |
| 31 | 13632008884201 |
| 32 | 40244583972480 |