The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | -3 |
| 1 | 0 |
| 2 | 12 |
| 3 | 60 |
| 4 | 252 |
| 5 | 1020 |
| 6 | 4092 |
| 7 | 16380 |
| 8 | 65532 |
| 9 | 262140 |
| 10 | 1048572 |
| 11 | 4194300 |
| 12 | 16777212 |
| 13 | 67108860 |
| 14 | 268435452 |
| 15 | 1073741820 |
| 16 | 4294967292 |
| 17 | 17179869180 |
| 18 | 68719476732 |
| 19 | 274877906940 |
| 20 | 1099511627772 |
| 21 | 4398046511100 |
| 22 | 17592186044412 |
| 23 | 70368744177660 |
| 24 | 281474976710652 |
| 25 | 1125899906842620 |
[-3,0,12,60,252,1020,4092,16380,65532,262140, 1048572,4194300,16777212,67108860,268435452, 1073741820,4294967292,17179869180,68719476732, 274877906940,1099511627772,4398046511100, 17592186044412,70368744177660,281474976710652, 1125899906842620] |