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 | 8 |
| 3 | 34 |
| 4 | 140 |
| 5 | 574 |
| 6 | 2348 |
| 7 | 9598 |
| 8 | 39224 |
| 9 | 160282 |
| 10 | 654944 |
| 11 | 2676202 |
| 12 | 10935332 |
| 13 | 44683222 |
| 14 | 182581508 |
| 15 | 746051878 |
| 16 | 3048465200 |
| 17 | 12456425842 |
| 18 | 50898577976 |
| 19 | 207978216754 |
| 20 | 849826072316 |
| 21 | 3472499977390 |
| 22 | 14189087019740 |
| 23 | 57978456949582 |