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) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 9 |
| 3 | 21 |
| 4 | 57 |
| 5 | 123 |
| 6 | 279 |
| 7 | 549 |
| 8 | 1209 |
| 9 | 2127 |
| 10 | 4689 |
| 11 | 7989 |
| 12 | 17031 |
| 13 | 28395 |
| 14 | 60615 |
| 15 | 98061 |
| 16 | 208569 |
| 17 | 334563 |
| 18 | 705789 |
| 19 | 1121877 |
| 20 | 2356737 |
| 21 | 3718827 |
| 22 | 7786359 |
| 23 | 12223077 |
| 24 | 25488903 |
| 25 | 39857523 |
| 26 | 82876257 |
| 27 | 129135729 |
| 28 | 267784119 |
| 29 | 416118219 |
| 30 | 860825439 |
| 31 | 1334448261 |
| 32 | 2754778809 |
| 33 | 4261609131 |
| 34 | 8781196329 |
| 35 | 13559714109 |
| 36 | 27893530029 |