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 | 4 |
| 2 | 30 |
| 3 | 146 |
| 4 | 517 |
| 5 | 1476 |
| 6 | 3614 |
| 7 | 7890 |
| 8 | 15761 |
| 9 | 29332 |
| 10 | 51526 |
| 11 | 86274 |
| 12 | 138725 |
| 13 | 215476 |
| 14 | 324822 |
| 15 | 477026 |
| 16 | 684609 |
| 17 | 962660 |
| 18 | 1329166 |
| 19 | 1805362 |
| 20 | 2416101 |
| 21 | 3190244 |
| 22 | 4161070 |
| 23 | 5366706 |
| 24 | 6850577 |
| 25 | 8661876 |
| 26 | 10856054 |
| 27 | 13495330 |
| 28 | 16649221 |
| 29 | 20395092 |
| 30 | 24818726 |