The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 16 |
| 4 | 64 |
| 5 | 256 |
| 6 | 4096 |
| 7 | 16384 |
| 8 | 65536 |
| 9 | 1048576 |
| 10 | 16777216 |
| 11 | 67108864 |
| 12 | 268435456 |
| 13 | 4294967296 |
| 14 | 17179869184 |
| 15 | 68719476736 |
| 16 | 274877906944 |
| 17 | 70368744177664 |
| 18 | 281474976710656 |
| 19 | 1125899906842624 |
| 20 | 4503599627370496 |
| 21 | 18014398509481984 |
| 22 | 72057594037927936 |
| 23 | 18446744073709551616 |
[1,4,16,64,256,4096,16384,65536,1048576,16777216, 67108864,268435456,4294967296,17179869184, 68719476736,274877906944,70368744177664, 281474976710656,1125899906842624,4503599627370496, 18014398509481984,72057594037927936, 18446744073709551616] |