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 | 2 |
| 3 | 16 |
| 4 | 52 |
| 5 | 160 |
| 6 | 9232 |
| 7 | 27700 |
| 8 | 83104 |
| 9 | 599056 |
| 10 | 1797172 |
| 11 | 5391520 |
| 12 | 38862808 |
| 13 | 131161984 |
| 14 | 393485956 |
| 15 | 1180457872 |
| 16 | 3541373620 |
| 17 | 10624120864 |
| 18 | 87327950740 |
| 19 | 261983852224 |
| 20 | 785951556676 |
| 21 | 2357854670032 |
| 22 | 7553654536192 |
| 23 | 22660963608580 |
| 24 | 67982890825744 |
| 25 | 203948672477236 |