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 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 23 |
| 5 | 62 |
| 6 | 161 |
| 7 | 410 |
| 8 | 1031 |
| 9 | 2579 |
| 10 | 6359 |
| 11 | 15575 |
| 12 | 37830 |
| 13 | 91241 |
| 14 | 218581 |
| 15 | 520544 |
| 16 | 1232431 |
| 17 | 2902644 |
| 18 | 6802178 |
| 19 | 15866054 |
| 20 | 36844016 |
| 21 | 85202436 |
| 22 | 196251933 |
| 23 | 450341874 |
| 24 | 1029709478 |
| 25 | 2346409350 |
| 26 | 5329371142 |
| 27 | 12066816905 |
| 28 | 27240224766 |
| 29 | 61317231288 |
| 30 | 137643961196 |