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 | 5 |
| 1 | 5 |
| 2 | 11 |
| 3 | 35 |
| 4 | 143 |
| 5 | 719 |
| 6 | 4319 |
| 7 | 30239 |
| 8 | 241919 |
| 9 | 2177279 |
| 10 | 21772799 |
| 11 | 239500799 |
| 12 | 2874009599 |
| 13 | 37362124799 |
| 14 | 523069747199 |
| 15 | 7846046207999 |
| 16 | 125536739327999 |
| 17 | 2134124568575999 |
| 18 | 38414242234367999 |
| 19 | 729870602452991999 |
| 20 | 14597412049059839999 |
| 21 | 306545653030256639999 |