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) |
|---|---|
| 4 | 30 |
| 5 | 8340 |
| 6 | 780242 |
| 7 | 29813578 |
| 8 | 657271645 |
| 9 | 10037038800 |
| 10 | 117733967666 |
| 11 | 1130702091428 |
| 12 | 9273992351046 |
| 13 | 66900184307860 |
| 14 | 433616524985590 |
| 15 | 2566055594813118 |
| 16 | 14037125952339998 |
| 17 | 71676448315103924 |
| 18 | 344320192201127730 |
| 19 | 1566076395413987110 |
| 20 | 6779944255517707576 |