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 | 2 |
| 2 | 6 |
| 3 | 22 |
| 4 | 54 |
| 5 | 132 |
| 6 | 292 |
| 7 | 626 |
| 8 | 1290 |
| 9 | 2594 |
| 10 | 5102 |
| 11 | 9864 |
| 12 | 18792 |
| 13 | 35362 |
| 14 | 65838 |
| 15 | 121454 |
| 16 | 222246 |
| 17 | 403788 |
| 18 | 728972 |
| 19 | 1308562 |
| 20 | 2336946 |
| 21 | 4154170 |
| 22 | 7353310 |
| 23 | 12965904 |
| 24 | 22781520 |
| 25 | 39897410 |
| 26 | 69662166 |
| 27 | 121292998 |
| 28 | 210642966 |
| 29 | 364928532 |
| 30 | 630794356 |