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 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 4 |
| 5 | 11 |
| 6 | 34 |
| 7 | 107 |
| 8 | 368 |
| 9 | 1284 |
| 10 | 4654 |
| 11 | 17072 |
| 12 | 63599 |
| 13 | 238590 |
| 14 | 901970 |
| 15 | 3426575 |
| 16 | 13079254 |
| 17 | 50107908 |
| 18 | 192622051 |
| 19 | 742624231 |
| 20 | 2870671949 |
| 21 | 11123060677 |
| 22 | 43191857687 |
| 23 | 168047007727 |
| 24 | 654999700402 |
| 25 | 2557227044763 |
| 26 | 9999088822074 |
| 27 | 39153010938486 |
| 28 | 153511100594602 |
| 29 | 602621953061977 |
| 30 | 2368347037571251 |
| 31 | 9317706529987949 |
| 32 | 36695016991712878 |