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 | 2 |
| 1 | 3 |
| 2 | 17 |
| 3 | 71 |
| 4 | 251 |
| 5 | 857 |
| 6 | 2767 |
| 7 | 8803 |
| 8 | 27211 |
| 9 | 82939 |
| 10 | 249779 |
| 11 | 744949 |
| 12 | 2201273 |
| 13 | 6463081 |
| 14 | 18858529 |
| 15 | 54764947 |
| 16 | 158330573 |
| 17 | 456016933 |
| 18 | 1309050653 |
| 19 | 3746543923 |
| 20 | 10694444393 |
| 21 | 30453898201 |
| 22 | 86534078387 |
| 23 | 245401348403 |
| 24 | 694683409429 |
| 25 | 1963275871663 |
| 26 | 5540095680547 |
| 27 | 15611517864749 |