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 | 9 |
| 3 | 41 |
| 4 | 177 |
| 5 | 649 |
| 6 | 2137 |
| 7 | 6375 |
| 8 | 17575 |
| 9 | 45207 |
| 10 | 109583 |
| 11 | 252117 |
| 12 | 553981 |
| 13 | 1168261 |
| 14 | 2374753 |
| 15 | 4669367 |
| 16 | 8908546 |
| 17 | 16535154 |
| 18 | 29927526 |
| 19 | 52925886 |
| 20 | 91617530 |
| 21 | 155484150 |
| 22 | 259062316 |
| 23 | 424306230 |
| 24 | 683919048 |
| 25 | 1085984406 |
| 26 | 1700352360 |
| 27 | 2627337510 |