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 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 16 |
| 4 | 81 |
| 5 | 301 |
| 6 | 1451 |
| 7 | 6231 |
| 8 | 29891 |
| 9 | 137731 |
| 10 | 666976 |
| 11 | 3193026 |
| 12 | 15658831 |
| 13 | 76719891 |
| 14 | 380788006 |
| 15 | 1894818776 |
| 16 | 9502977851 |
| 17 | 47822585931 |
| 18 | 241944876266 |
| 19 | 1228151169656 |
| 20 | 6258922649451 |
| 21 | 31992657321551 |
| 22 | 164040821525031 |