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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 5 |
| 5 | 13 |
| 6 | 31 |
| 7 | 79 |
| 8 | 213 |
| 9 | 606 |
| 10 | 1863 |
| 11 | 5853 |
| 12 | 19505 |
| 13 | 67257 |
| 14 | 235631 |
| 15 | 850352 |
| 16 | 3194167 |
| 17 | 12434883 |
| 18 | 48949883 |
| 19 | 198812307 |
| 20 | 823245530 |
| 21 | 3440622312 |
| 22 | 14763161313 |
| 23 | 64397952985 |
| 24 | 287520444756 |
| 25 | 1321070444052 |
| 26 | 6152237618431 |
| 27 | 28838910052201 |