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 | 18 |
| 2 | 198 |
| 3 | 2006 |
| 4 | 19980 |
| 5 | 199994 |
| 6 | 1999986 |
| 7 | 20000010 |
| 8 | 199999996 |
| 9 | 1999999944 |
| 10 | 19999999986 |
| 11 | 199999999980 |
| 12 | 2000000000028 |
| 13 | 20000000000008 |
| 14 | 200000000000004 |
| 15 | 2000000000000026 |
| 16 | 19999999999999998 |
| 17 | 200000000000000000 |
| 18 | 1999999999999999992 |
| 19 | 20000000000000000012 |
| 20 | 200000000000000000028 |