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 | 4 |
| 3 | 0 |
| 4 | 13 |
| 5 | 209 |
| 6 | 0 |
| 7 | 1231 |
| 8 | 739 |
| 9 | 0 |
| 10 | 51850 |
| 11 | 129587 |
| 12 | 0 |
| 13 | 657067 |
| 14 | 868120 |
| 15 | 0 |
| 16 | 8400886 |
| 17 | 91426058 |
| 18 | 0 |
| 19 | 859535812 |
| 20 | 1483912651 |
| 21 | 0 |
| 22 | 30374372956 |
| 23 | 68688648677 |
| 24 | 0 |
| 25 | 422259655777 |
| 26 | 2129293909882 |
| 27 | 0 |
| 28 | 11623487749588 |
| 29 | 44275834126985 |
| 30 | 0 |
| 31 | 329933248712302 |
| 32 | 971441847750184 |
| 33 | 0 |
| 34 | 927342285792613 |