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 | 1 |
| 3 | 4 |
| 4 | 12 |
| 5 | 41 |
| 6 | 133 |
| 7 | 485 |
| 8 | 1752 |
| 9 | 6677 |
| 10 | 25809 |
| 11 | 102130 |
| 12 | 409532 |
| 13 | 1665128 |
| 14 | 6837348 |
| 15 | 28333334 |
| 16 | 118288386 |
| 17 | 497120101 |
| 18 | 2101181482 |
| 19 | 8926401690 |
| 20 | 38093403136 |
| 21 | 163224292328 |
| 22 | 701951448268 |
| 23 | 3028792691947 |
| 24 | 13108224143298 |
| 25 | 56887750453404 |
| 26 | 247512117880754 |
| 27 | 1079421026637431 |