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A129539 Composite numbers to composite powers. 1
256, 1296, 4096, 6561, 10000, 20736, 38416, 46656, 50625, 65536, 104976, 160000, 194481, 234256, 262144, 331776, 390625, 456976, 531441, 614656, 810000, 1000000, 1048576, 1185921, 1336336, 1500625, 1679616, 2085136, 2313441 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Only unique powers are shown here. E.g., 4096 = 4^6 = 8^4, but 4096 is only in the sequence once. - Franklin T. Adams-Watters, Sep 28 2011

LINKS

Table of n, a(n) for n=0..28.

EXAMPLE

The sequence starts with 256, because 256 is the smallest composite number to the smallest composite power.

MATHEMATICA

comp = Select[Range[2, 40], ! PrimeQ[ # ] &]; Select[ Union[Flatten[ Table[comp[[n]]^comp[[k]], {n, Length[comp]}, {k, Length[comp]}]]], # < comp[[Length[comp]]]^4 &]

CROSSREFS

Cf. A113877 - Semiprimes to semiprime powers - is a subsequence of this sequence.

Sequence in context: A120054 A237952 A237235 * A113877 A237398 A237392

Adjacent sequences:  A129536 A129537 A129538 * A129540 A129541 A129542

KEYWORD

nonn

AUTHOR

Tanya Khovanova, May 29 2007

STATUS

approved

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Last modified August 21 17:33 EDT 2017. Contains 290891 sequences.