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 | 6 |
| 3 | 18 |
| 4 | 48 |
| 5 | 131 |
| 6 | 363 |
| 7 | 1017 |
| 8 | 2873 |
| 9 | 8169 |
| 10 | 23349 |
| 11 | 67024 |
| 12 | 193086 |
| 13 | 557949 |
| 14 | 1616501 |
| 15 | 4694034 |
| 16 | 13657896 |
| 17 | 39809649 |
| 18 | 116218701 |
| 19 | 339762942 |
| 20 | 994553160 |
| 21 | 2914608177 |
| 22 | 8550424953 |
| 23 | 25107964077 |
| 24 | 73793368593 |
| 25 | 217057617567 |
| 26 | 638936722403 |
| 27 | 1882096946232 |
| 28 | 5547613247418 |