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 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 49 |
| 6 | 263 |
| 7 | 1653 |
| 8 | 11877 |
| 9 | 95991 |
| 10 | 862047 |
| 11 | 8516221 |
| 12 | 91782159 |
| 13 | 1071601285 |
| 14 | 13473914281 |
| 15 | 181517350571 |
| 16 | 2608383775171 |
| 17 | 39824825088809 |
| 18 | 643813226048935 |
| 19 | 10986188094959045 |
| 20 | 197337931571468445 |
| 21 | 3721889002400665951 |
| 22 | 73539326922210382215 |
| 23 | 1519081379788242418149 |
| 24 | 32743555520207058219615 |
| 25 | 735189675389014372317381 |