A171217 Numbers of the form (noncomposite number)^(noncomposite number), but not p^p where p is prime.

1, 2, 3, 5, 7, 8, 9, 11, 13, 17, 19, 23, 25, 29, 31, 32, 37, 41, 43, 47, 49, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 121, 125, 127, 128, 131, 137, 139, 149, 151, 157, 163, 167, 169, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239

Offset

1,2

Comments

The union of {1}, the primes A000040, and powers of the form p^q where p and q are distinct primes.

Links

Table of n, a(n) for n=1..62.

Crossrefs

Cf. A000961, A005117, A008578, A051674.

Sequence in context: A359059 A328320 A086539 * A344591 A049468 A187332

Adjacent sequences: A171214 A171215 A171216 * A171218 A171219 A171220

Keyword

nonn

Author

Juri-Stepan Gerasimov, Dec 05 2009

Extensions

Attribute "power-free" removed from the definition by R. J. Mathar, Dec 09 2009

Inserted a(19)=43 by Gionata Neri, Dec 28 2015

Status

approved