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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 5 |
| 4 | 13 |
| 5 | 151 |
| 6 | 463 |
| 7 | 2957 |
| 8 | 9725 |
| 9 | 261739 |
| 10 | 896507 |
| 11 | 6231571 |
| 12 | 21920539 |
| 13 | 311583955 |
| 14 | 1116869179 |
| 15 | 8066939069 |
| 16 | 29323723037 |
| 17 | 1715310801971 |
| 18 | 6303146700755 |
| 19 | 46534580965463 |
| 20 | 172479371522639 |
| 21 | 2566609537700489 |
| 22 | 9580228898547889 |
| 23 | 71737644622567835 |
| 24 | 269340391562396747 |
| 25 | 8110742483462690623 |
| 26 | 30602551916179033519 |