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 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 12 |
| 4 | 36 |
| 5 | 98 |
| 6 | 250 |
| 7 | 616 |
| 8 | 1484 |
| 9 | 3508 |
| 10 | 8140 |
| 11 | 18620 |
| 12 | 42164 |
| 13 | 94632 |
| 14 | 210518 |
| 15 | 464840 |
| 16 | 1020556 |
| 17 | 2229014 |
| 18 | 4843316 |
| 19 | 10476164 |
| 20 | 22576728 |
| 21 | 48489154 |
| 22 | 103790370 |
| 23 | 221484824 |
| 24 | 471427432 |
| 25 | 1001027226 |
| 26 | 2120503144 |
| 27 | 4482083616 |
| 28 | 9455815160 |
| 29 | 19913405076 |
| 30 | 41862056992 |
| 31 | 87857540836 |