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 | 5 |
| 2 | 15 |
| 3 | 42 |
| 4 | 113 |
| 5 | 297 |
| 6 | 767 |
| 7 | 1957 |
| 8 | 4947 |
| 9 | 12419 |
| 10 | 31006 |
| 11 | 77067 |
| 12 | 190855 |
| 13 | 471214 |
| 14 | 1160452 |
| 15 | 2851731 |
| 16 | 6995305 |
| 17 | 17133294 |
| 18 | 41909286 |
| 19 | 102399361 |
| 20 | 249960246 |
| 21 | 609662706 |
| 22 | 1485944622 |
| 23 | 3619527395 |
| 24 | 8811972483 |
| 25 | 21443566290 |
| 26 | 52161461882 |
| 27 | 126839318918 |