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 | 1 |
| 2 | 21 |
| 3 | 303 |
| 4 | 4006 |
| 5 | 50010 |
| 6 | 600015 |
| 7 | 7000021 |
| 8 | 80000028 |
| 9 | 900000036 |
| 10 | 10000000045 |
| 11 | 110000000055 |
| 12 | 1200000000066 |
| 13 | 13000000000078 |
| 14 | 140000000000091 |
| 15 | 1500000000000105 |
| 16 | 16000000000000120 |
| 17 | 170000000000000136 |
| 18 | 1800000000000000153 |
| 19 | 19000000000000000171 |
| 20 | 200000000000000000190 |
| 21 | 2100000000000000000210 |
| 22 | 22000000000000000000231 |