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 | 4 |
| 2 | 14 |
| 3 | 46 |
| 4 | 162 |
| 5 | 574 |
| 6 | 2042 |
| 7 | 7270 |
| 8 | 25890 |
| 9 | 92206 |
| 10 | 328394 |
| 11 | 1169590 |
| 12 | 4165554 |
| 13 | 14835838 |
| 14 | 52838618 |
| 15 | 188187526 |
| 16 | 670239810 |
| 17 | 2387094478 |
| 18 | 8501763050 |
| 19 | 30279478102 |
| 20 | 107841960402 |
| 21 | 384084837406 |
| 22 | 1367938433018 |
| 23 | 4871984973862 |