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 | 3 |
| 3 | 7 |
| 4 | 13 |
| 5 | 61 |
| 6 | 181 |
| 7 | 1261 |
| 8 | 2521 |
| 9 | 7561 |
| 10 | 37801 |
| 11 | 415801 |
| 12 | 1247401 |
| 13 | 16216201 |
| 14 | 113513401 |
| 15 | 567567001 |
| 16 | 1135134001 |
| 17 | 19297278001 |
| 18 | 57891834001 |
| 19 | 1099944846001 |
| 20 | 5499724230001 |
| 21 | 38498069610001 |
| 22 | 423478765710001 |
| 23 | 9740011611330001 |