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 | 5 |
| 3 | 19 |
| 4 | 63 |
| 5 | 191 |
| 6 | 543 |
| 7 | 1471 |
| 8 | 3839 |
| 9 | 9727 |
| 10 | 24063 |
| 11 | 58367 |
| 12 | 139263 |
| 13 | 327679 |
| 14 | 761855 |
| 15 | 1753087 |
| 16 | 3997695 |
| 17 | 9043967 |
| 18 | 20316159 |
| 19 | 45350911 |
| 20 | 100663295 |
| 21 | 222298111 |
| 22 | 488636415 |
| 23 | 1069547519 |
| 24 | 2332033023 |
| 25 | 5066719231 |
| 26 | 10972299263 |
| 27 | 23689428991 |
| 28 | 51002736639 |
| 29 | 109521666047 |
| 30 | 234612588543 |
| 31 | 501437431807 |