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 | 2 |
| 2 | 4 |
| 3 | 12 |
| 4 | 27 |
| 5 | 70 |
| 6 | 182 |
| 7 | 477 |
| 8 | 1269 |
| 9 | 3413 |
| 10 | 9249 |
| 11 | 25255 |
| 12 | 69389 |
| 13 | 191680 |
| 14 | 532026 |
| 15 | 1482926 |
| 16 | 4148949 |
| 17 | 11647260 |
| 18 | 32797042 |
| 19 | 92608175 |
| 20 | 262157690 |
| 21 | 743845685 |
| 22 | 2115093984 |
| 23 | 6026041793 |
| 24 | 17199956143 |
| 25 | 49176678286 |
| 26 | 140824260498 |
| 27 | 403865784020 |