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) |
|---|---|
| 3 | 1 |
| 4 | 7 |
| 5 | 27 |
| 6 | 83 |
| 7 | 239 |
| 8 | 659 |
| 9 | 1781 |
| 10 | 4751 |
| 11 | 12583 |
| 12 | 33175 |
| 13 | 87231 |
| 14 | 228983 |
| 15 | 600473 |
| 16 | 1573655 |
| 17 | 4122467 |
| 18 | 10796939 |
| 19 | 28273519 |
| 20 | 74031979 |
| 21 | 193835949 |
| 22 | 507497759 |
| 23 | 1328692751 |
| 24 | 3478637807 |
| 25 | 9107313407 |
| 26 | 23843452463 |
| 27 | 62423286769 |
| 28 | 163426800679 |
| 29 | 427857750891 |
| 30 | 1120147480451 |