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 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 23 |
| 6 | 63 |
| 7 | 155 |
| 8 | 448 |
| 9 | 1152 |
| 10 | 3452 |
| 11 | 9158 |
| 12 | 28178 |
| 13 | 76539 |
| 14 | 240370 |
| 15 | 665129 |
| 16 | 2123439 |
| 17 | 5964691 |
| 18 | 19302316 |
| 19 | 54898417 |
| 20 | 179696558 |
| 21 | 516468943 |
| 22 | 1707136794 |
| 23 | 4950706511 |
| 24 | 16503342067 |
| 25 | 48232628420 |
| 26 | 161984027241 |
| 27 | 476636439213 |
| 28 | 1611286734027 |
| 29 | 4769639146736 |
| 30 | 16218693724179 |