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 | 5 |
| 2 | 19 |
| 3 | 67 |
| 4 | 227 |
| 5 | 751 |
| 6 | 2445 |
| 7 | 7869 |
| 8 | 25107 |
| 9 | 79567 |
| 10 | 250793 |
| 11 | 786985 |
| 12 | 2460397 |
| 13 | 7667921 |
| 14 | 23832931 |
| 15 | 73902627 |
| 16 | 228692115 |
| 17 | 706407903 |
| 18 | 2178511449 |
| 19 | 6708684009 |
| 20 | 20632428249 |
| 21 | 63380014845 |
| 22 | 194486530791 |
| 23 | 596213956023 |
| 24 | 1826103432573 |
| 25 | 5588435470401 |
| 26 | 17089296473655 |