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 | 3 |
| 3 | 10 |
| 4 | 43 |
| 5 | 216 |
| 6 | 1241 |
| 7 | 7988 |
| 8 | 56763 |
| 9 | 440254 |
| 10 | 3693728 |
| 11 | 33281359 |
| 12 | 320112326 |
| 13 | 3270177860 |
| 14 | 35329070470 |
| 15 | 402128329243 |
| 16 | 4806784533967 |
| 17 | 60166803598106 |
| 18 | 786622663286330 |
| 19 | 10717555856584617 |
| 20 | 151864784070048105 |