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 | 23 |
| 2 | 152 |
| 3 | 1107 |
| 4 | 8611 |
| 5 | 70478 |
| 6 | 1793210 |
| 7 | 5156463 |
| 8 | 45470645 |
| 9 | 2074530409 |
| 10 | 11397691034 |
| 11 | 33578243459 |
| 12 | 1603686087003 |
| 13 | 2859644709998 |
| 14 | 26622184513952 |
| 15 | 518238694402971 |
| 16 | 2339285051888769 |
| 17 | 69641948074252447 |
| 18 | 208626752630607267 |
| 19 | 8383527978057824838 |
| 20 | 119921750787289924042 |
| 21 | 375732914981870085595 |