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 | 7 |
| 3 | 28 |
| 4 | 127 |
| 5 | 406 |
| 6 | 1756 |
| 7 | 5104 |
| 8 | 20575 |
| 9 | 61237 |
| 10 | 230122 |
| 11 | 649540 |
| 12 | 2579932 |
| 13 | 6908734 |
| 14 | 26044984 |
| 15 | 74578888 |
| 16 | 269985151 |
| 17 | 731794258 |
| 18 | 2799670555 |
| 19 | 7360989292 |
| 20 | 27392181562 |
| 21 | 75948764752 |
| 22 | 268482753172 |
| 23 | 721764371008 |
| 24 | 2742292424188 |
| 25 | 7078172334031 |
| 26 | 25701091008418 |
| 27 | 71173405454680 |