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 | 8 |
| 3 | 20 |
| 4 | 51 |
| 5 | 133 |
| 6 | 356 |
| 7 | 972 |
| 8 | 2695 |
| 9 | 7557 |
| 10 | 21372 |
| 11 | 60840 |
| 12 | 174097 |
| 13 | 500295 |
| 14 | 1442720 |
| 15 | 4172752 |
| 16 | 12099411 |
| 17 | 35161001 |
| 18 | 102375400 |
| 19 | 298586652 |
| 20 | 872177273 |
| 21 | 2551118623 |
| 22 | 7471195500 |
| 23 | 21904500500 |
| 24 | 64286141881 |
| 25 | 188844619563 |
| 26 | 555216323396 |
| 27 | 1633658183432 |
| 28 | 4810340397375 |
| 29 | 14173698242137 |