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 | 5 |
| 3 | 23 |
| 4 | 105 |
| 5 | 449 |
| 6 | 1902 |
| 7 | 7828 |
| 8 | 31976 |
| 9 | 129200 |
| 10 | 520425 |
| 11 | 2088217 |
| 12 | 8371186 |
| 13 | 33514797 |
| 14 | 134140430 |
| 15 | 536699674 |
| 16 | 2147154667 |
| 17 | 8589198795 |
| 18 | 34358341823 |
| 19 | 137435830265 |
| 20 | 549749857574 |
| 21 | 2199010044813 |
| 22 | 8796067657649 |
| 23 | 35184315676573 |
| 24 | 140737380485376 |
| 25 | 562949713881526 |