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 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 21 |
| 5 | 61 |
| 6 | 295 |
| 7 | 1331 |
| 8 | 10409 |
| 9 | 65017 |
| 10 | 694411 |
| 11 | 5454879 |
| 12 | 73145149 |
| 13 | 689074101 |
| 14 | 11090013103 |
| 15 | 121652191051 |
| 16 | 2282132463953 |
| 17 | 28550033871857 |
| 18 | 611369381873683 |
| 19 | 8587415858721079 |
| 20 | 206626962757626981 |
| 21 | 3219065122124476717 |