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 | 7 |
| 3 | 31 |
| 4 | 121 |
| 5 | 456 |
| 6 | 1709 |
| 7 | 6427 |
| 8 | 24301 |
| 9 | 92368 |
| 10 | 352705 |
| 11 | 1352066 |
| 12 | 5200287 |
| 13 | 20058286 |
| 14 | 77558745 |
| 15 | 300540179 |
| 16 | 1166803093 |
| 17 | 4537567632 |
| 18 | 17672631881 |
| 19 | 68923264390 |
| 20 | 269128937199 |
| 21 | 1052049481838 |
| 22 | 4116715363777 |
| 23 | 16123801841526 |
| 24 | 63205303218851 |
| 25 | 247959266474026 |
| 26 | 973469712824029 |