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 | 1 |
| 3 | 5 |
| 4 | 17 |
| 5 | 52 |
| 6 | 148 |
| 7 | 408 |
| 8 | 1101 |
| 9 | 2937 |
| 10 | 7777 |
| 11 | 20504 |
| 12 | 53912 |
| 13 | 141520 |
| 14 | 371113 |
| 15 | 972573 |
| 16 | 2547825 |
| 17 | 6672876 |
| 18 | 17473996 |
| 19 | 45754280 |
| 20 | 119797205 |
| 21 | 313650865 |
| 22 | 821177281 |
| 23 | 2149916400 |
| 24 | 5628629232 |
| 25 | 14736064032 |
| 26 | 38579712913 |
| 27 | 101003317493 |
| 28 | 264430632401 |
| 29 | 692289215332 |
| 30 | 1812438042052 |