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) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 9 |
| 4 | 31 |
| 5 | 71 |
| 6 | 244 |
| 7 | 559 |
| 8 | 1921 |
| 9 | 4401 |
| 10 | 15124 |
| 11 | 34649 |
| 12 | 119071 |
| 13 | 272791 |
| 14 | 937444 |
| 15 | 2147679 |
| 16 | 7380481 |
| 17 | 16908641 |
| 18 | 58106404 |
| 19 | 133121449 |
| 20 | 457470751 |
| 21 | 1048062951 |
| 22 | 3601659604 |
| 23 | 8251382159 |
| 24 | 28355806081 |
| 25 | 64962994321 |
| 26 | 223244789044 |
| 27 | 511452572409 |
| 28 | 1757602506271 |
| 29 | 4026657584951 |