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 | 4 |
| 3 | 15 |
| 4 | 54 |
| 5 | 185 |
| 6 | 608 |
| 7 | 1939 |
| 8 | 6058 |
| 9 | 18669 |
| 10 | 57012 |
| 11 | 173063 |
| 12 | 523262 |
| 13 | 1577953 |
| 14 | 4750216 |
| 15 | 14283387 |
| 16 | 42915666 |
| 17 | 128878037 |
| 18 | 386896220 |
| 19 | 1161212911 |
| 20 | 3484687270 |
| 21 | 10456158921 |
| 22 | 31372671024 |
| 23 | 94126401635 |
| 24 | 282395982074 |
| 25 | 847221500605 |
| 26 | 2541731610628 |
| 27 | 7625329049559 |