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 | 3 |
| 3 | 9 |
| 4 | 18 |
| 5 | 36 |
| 6 | 78 |
| 7 | 169 |
| 8 | 364 |
| 9 | 784 |
| 10 | 1680 |
| 11 | 3600 |
| 12 | 7740 |
| 13 | 16641 |
| 14 | 35733 |
| 15 | 76729 |
| 16 | 164815 |
| 17 | 354025 |
| 18 | 760410 |
| 19 | 1633284 |
| 20 | 3508110 |
| 21 | 7535025 |
| 22 | 16184520 |
| 23 | 34762816 |
| 24 | 74666944 |
| 25 | 160376896 |
| 26 | 344473464 |
| 27 | 739894401 |
| 28 | 1589218425 |
| 29 | 3413480625 |
| 30 | 7331811675 |