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 | 5 |
| 3 | 15 |
| 4 | 33 |
| 5 | 83 |
| 6 | 197 |
| 7 | 479 |
| 8 | 1153 |
| 9 | 2787 |
| 10 | 6725 |
| 11 | 16239 |
| 12 | 39201 |
| 13 | 94643 |
| 14 | 228485 |
| 15 | 551615 |
| 16 | 1331713 |
| 17 | 3215043 |
| 18 | 7761797 |
| 19 | 18738639 |
| 20 | 45239073 |
| 21 | 109216787 |
| 22 | 263672645 |
| 23 | 636562079 |
| 24 | 1536796801 |
| 25 | 3710155683 |
| 26 | 8957108165 |
| 27 | 21624372015 |
| 28 | 52205852193 |
| 29 | 126036076403 |
| 30 | 304278004997 |