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 | 12 |
| 5 | 57 |
| 6 | 300 |
| 7 | 1697 |
| 8 | 10126 |
| 9 | 62991 |
| 10 | 405247 |
| 11 | 2680901 |
| 12 | 18160444 |
| 13 | 125562250 |
| 14 | 883868590 |
| 15 | 6321838520 |
| 16 | 45869309028 |
| 17 | 337167193262 |
| 18 | 2508018933431 |
| 19 | 18861358215299 |
| 20 | 143293615189089 |
| 21 | 1098997404472941 |
| 22 | 8504070741463729 |
| 23 | 66358269984208701 |
| 24 | 521923129718567918 |
| 25 | 4136089275165532156 |
| 26 | 33013640650845937124 |