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 | 12 |
| 2 | 46 |
| 3 | 170 |
| 4 | 630 |
| 5 | 2352 |
| 6 | 8844 |
| 7 | 33462 |
| 8 | 127270 |
| 9 | 486200 |
| 10 | 1864356 |
| 11 | 7171892 |
| 12 | 27665596 |
| 13 | 106977600 |
| 14 | 414538200 |
| 15 | 1609344270 |
| 16 | 6258307590 |
| 17 | 24373220520 |
| 18 | 95050101300 |
| 19 | 371125269900 |
| 20 | 1450670612820 |
| 21 | 5676173948640 |
| 22 | 22230262964520 |
| 23 | 87137141867100 |
| 24 | 341824599040860 |
| 25 | 1341897206800752 |