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 | 2 |
| 3 | 7 |
| 4 | 26 |
| 5 | 107 |
| 6 | 462 |
| 7 | 2074 |
| 8 | 9572 |
| 9 | 45147 |
| 10 | 216638 |
| 11 | 1054254 |
| 12 | 5190710 |
| 13 | 25810064 |
| 14 | 129423512 |
| 15 | 653740518 |
| 16 | 3323270096 |
| 17 | 16988894131 |
| 18 | 87283137130 |
| 19 | 450434292624 |
| 20 | 2333851816654 |
| 21 | 12136369892776 |
| 22 | 63318984098996 |
| 23 | 331347363084737 |
| 24 | 1738713937163124 |
| 25 | 9146850725274636 |