The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2047 |
| 3 | 88573 |
| 4 | 2794155 |
| 5 | 12207031 |
| 6 | 181308931 |
| 7 | 329554457 |
| 8 | 3269560515 |
| 9 | 5883904390 |
| 10 | 24987792457 |
| 11 | 28531167061 |
| 12 | 247486690815 |
| 13 | 149346699503 |
| 14 | 674597973479 |
| 15 | 1081213356763 |
| 16 | 3571013994483 |
| 17 | 2141993519227 |
| 18 | 12044352286330 |
| 19 | 6471681049901 |
| 20 | 34108336703805 |
| 21 | 29189626919861 |
[1,2047,88573,2794155,12207031,181308931, 329554457,3269560515,5883904390,24987792457, 28531167061,247486690815,149346699503, 674597973479,1081213356763,3571013994483, 2141993519227,12044352286330,6471681049901, 34108336703805,29189626919861] |