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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 26 |
| 8 | 142 |
| 9 | 544 |
| 10 | 1826 |
| 11 | 5651 |
| 12 | 16859 |
| 13 | 49739 |
| 14 | 147605 |
| 15 | 437656 |
| 16 | 1292876 |
| 17 | 3795660 |
| 18 | 11066720 |
| 19 | 32052260 |
| 20 | 92323188 |
| 21 | 264835528 |
| 22 | 757301423 |
| 23 | 2159899295 |
| 24 | 6146377790 |
| 25 | 17454698660 |
| 26 | 49473876635 |
| 27 | 139980358007 |
| 28 | 395414558802 |
| 29 | 1115322187106 |
| 30 | 3141769710776 |