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 | 2 |
| 2 | 5 |
| 3 | 18 |
| 4 | 65 |
| 5 | 218 |
| 6 | 693 |
| 7 | 2138 |
| 8 | 6497 |
| 9 | 19602 |
| 10 | 58949 |
| 11 | 177026 |
| 12 | 531297 |
| 13 | 1594154 |
| 14 | 4782773 |
| 15 | 14348682 |
| 16 | 43046465 |
| 17 | 129139874 |
| 18 | 387420165 |
| 19 | 1162261106 |
| 20 | 3486784001 |
| 21 | 10460352762 |
| 22 | 31381059125 |
| 23 | 94143178298 |
| 24 | 282429535905 |
| 25 | 847288608818 |