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 | 7 |
| 3 | 35 |
| 4 | 156 |
| 5 | 670 |
| 6 | 2886 |
| 7 | 12797 |
| 8 | 59537 |
| 9 | 294585 |
| 10 | 1562324 |
| 11 | 8900568 |
| 12 | 54346140 |
| 13 | 353937741 |
| 14 | 2444771767 |
| 15 | 17814457447 |
| 16 | 136308242144 |
| 17 | 1091001532590 |
| 18 | 9105746802826 |
| 19 | 79041398643849 |
| 20 | 711994012088297 |
| 21 | 6642697774712213 |